Here's an almost complete list of Sing Out from Volume 1, Issue 1 back in May 1950 through Volume 34, Issue 4 in 1993.

Volume 1        Issue 1        The Hammer Song (Seeger)        May-50
Volume 1        Issue 2        Springtime Orchestra               Jun-50
Volume 1        Issue 3        Walk In Peace                        Jul-50
Volume 1        Issue 4        Headlines                        Aug-50
Volume 1        Issue 5        Police "Peace Catcher"               Sep-50
Volume 1        Issue 6        Photographers                        Oct-50
Volume 1        Issue 7        Snowman w/ Banjo               Dec-50
Volume 1        Issue 8                                         Jan-51
Volume 1        Issue 9                                         Feb-51
Volume 1        Issue 10 Wash Vigil for Martinsville 7 Mar-51
Volume 1        Issue 11 Song Lyrics                        Apr-51
Volume 1        Issue 12 French Peace Song               May-51
                        
Volume 2        Issue 1        First Anniversary Issue               Jul-51
Volume 2        Issue 2        Les Deportados                        Aug-51
Volume 2        Issue 3        "We've Always Welcomed Strangers" Sep-51
Volume 2        Issue 4        Halloween Pumpkin Issue               Oct-51
Volume 2        Issue 5        Josephine Baker                        Nov-51
Volume 2        Issue 6        Peace on Earth                        Dec-51
Volume 2        Issue 7        Construction Worker               Jan-52
Volume 2        Issue 8        Lead Belly                        Feb-52
Volume 2        Issue 9        Singing Trio                        Mar-52
Volume 2        Issue 10 Sit Down, Sit Down               Apr-52
Volume 2        Issue 11 Black Cover (poem to Robeson)        Oct-52
Volume 2        Issue 12 The Troubador                        Nov-52
                        
Volume 3        Issue 1        Earl Robinson                        Sep-52
Volume 3        Issue 2        Earl Robinson                        Oct-52
Volume 3        Issue 3        Ethel Rosenberg Letter               Nov-52
Volume 3        Issue 4        Man in Handcuffs               Dec-52
Volume 3        Issue 5        Robert Burns                        Jan-53
Volume 3        Issue 6        Mrs Ingram and Her Two Sons        Feb-53
Volume 3        Issue 7        Women of Spain                        Mar-53
Volume 3        Issue 8        Prokofiev                        Apr-53
Volume 3        Issue 9        "Juan"                         May-53
Volume 3        Issue 10 Betty Sanders                        Jun-53
Volume 3        Issue 11 Calypso                        Oct-53
Volume 3        Issue 12 Woody Guthrie                        Nov-53
                        
Volume 4        Issue 1        Irwin Silber (3rd Anniversary)        Dec-53
Volume 4        Issue 2        Man/Woman Holding Hands               Jan-54
Volume 4        Issue 3        Harmonica Breakdown               Feb-54
Volume 4        Issue 4        Songs From Australia               Mar-54
Volume 4        Issue 5        Old Satch                        Apr-54
Volume 4        Issue 6        Pete Seeger                        May-54
Volume 4        Issue 7                                        Fall -54
                         
Volume 5        Issue 1        Banjo                                Winter 55
Volume 5        Issue 2        Scottish Folk                        Spring 55
Volume 5        Issue 3        Steamboat Cover                Summer 55
Volume 5        Issue 4        Foolish Frog                        Autumn 55
                        
Volume 6        Issue 1        Fifth Anniversary Issue               Winter 1956
Volume 6        Issue 2        Songs From India               Spring 1956
Volume 6        Issue 3        The Long Song-Seller               Summer 1956
Volume 6        Issue 4        Julia Ward Howe                        Winter 1957
                        
Volume 7        Issue 1        Big Bill Broonzy               Spring 1957
Volume 7        Issue 2        Woody Guthrie                        Summer 1957
Volume 7        Issue 3        Jean Ritchie                        Fall 1957
Volume 7        Issue 4        A.L. Lloyd                        Winter 1958
                        
Volume 8        Issue 1        Odetta                                Spring 1958
Volume 8        Issue 2        Blue (man/women singing)        Summer 1958
Volume 8        Issue 3        Jerry Silverman                        Winter 1959
Volume 8        Issue 4        Richard Dyer-Bennet               Spring 1959
                        
Volume 9        Issue 1        Alan Lomax                        Summer 1959
Volume 9        Issue 2        Sonny Terry                        Fall 1959
Volume 9        Issue 3        Ewan McColl                        Winter 59/60
Volume 9        Issue 4        Rev Gary Davis                        Feb/March 1960
                        
Volume 10        Issue 1        Theodore Bikel                        April/May 1960
Volume 10        Issue 2        Guy Carawan                        Summer 1960
Volume 10        Issue 3        Lightning Hopkins               Oct/Nov 1960
Volume 10        Issue 4        Alan Mills                        Dec/Jan 60/61
                        
Volume 11        Issue 1        Pete Seeger (10th Anniversary)        Feb/March 1961
Volume 11        Issue 2        Clancy Bros w/ Tommy Makem        April/May 1961
Volume 11        Issue 3        Memphis Slim                        Summer 1961
Volume 11        Issue 4        Cisco Houston                        Oct/Nov 1961
Volume 11        Issue 5        New Lost City Ramblers               Dec/Jan 61/62
                        
Volume 12        Issue 1        Ella Jenkins                        Feb/March 1962
Volume 12        Issue 2        Earl Scruggs                        April/May 1962
Volume 12        Issue 3        Peggy Seeger                        Summer 1962
Volume 12        Issue 4        Bob Dylan                        Oct/Nov 1962
Volume 12        Issue 5        Freedom Songs, Albany, GA        Dec/Jan 1962
                        
Volume 13        Issue 1        Bill Monroe                        Feb/March 1963
Volume 13        Issue 2        Horton Barker                        April/May 1963
Volume 13        Issue 3        Joan Baez                        Summer 1963
Volume 13        Issue 4        The Old and The New               Oct/Nov 1963
Volume 13        Issue 5        Calhoun's Jug Stompers          Dec 63/Jan 64
                        
Volume 14        Issue 1        Bill Monroe/Doc Watson               Feb/March 1964
Volume 14        Issue 2        Carter/Schwartz/Cohan               April/May 1964
Volume 14        Issue 3        Mike Seeger                        Jul-64
Volume 14        Issue 4        Elizabeth Cotten               Sep-64
Volume 14        Issue 5        Mississippi John Hurt               Nov-64
Volume 14        Issue 6        Broadside Hoot-NYC               Jan-65
                        
Volume 15        Issue 1        Lead Belly                        Mar-65
Volume 15        Issue 2        Johnny Cash                        May-65
Volume 15        Issue 3        Protesters in Selma               Jul-65
Volume 15        Issue 4        Peanuts                                Sep-65
Volume 15        Issue 5        Newport 65-Dylan Goes Electric Nov-65
Volume 15        Issue 6        Peter La Farge                        Jan-66
                        
Volume 16        Issue 1        15th Anniversary               Feb/March 1966
Volume 16        Issue 2        Rackensack Tribe of Timbo, AK        April/May 1966
Volume 16        Issue 3        Pencil Drawing                        Jul-66
Volume 16        Issue 4        Newport Folk Festival               Sep-66
Volume 16        Issue 5        Songs of the Delano Grape Strikers Nov-66
Volume 16        Issue 6        Irwin Rosenhouse Drawing        Jan-67
                        
Volume 17        Issue 1        Mississippi John Hurt               Feb/March 1967
Volume 17        Issue 2        Eric Von Schmidt Art               April/May 1967
Volume 17        Issue 3        Sleepy John Estes               Jun/July 1967
Volume 17        Issue 4        George Phippen Painting         Aug/Sept 1967
Volume 17        Issue 5        Lady w/ Glasses                        Nov/Dec 1967
Volume 17        Issue 6        Thanh Hoa Province, N. Vietnam        Dec/Jan 67/68
                        
Volume 18        Issue 1        Homeless Man                     March/April 1968
Volume 18        Issue 2/3    Country Joe and the Fish    June/July 1968
Volume 18        Issue 3        Richie Havens Interview              Aug/Sept 1968
Volume 18        Issue 4        Painting by George Phippen    Aug/Sept 1968
Volume 18        Issue 5        Roger McGuinn Interview              Dec 68/Jan 69
Volume 18        Issue 6        Pencil Drawing                     Feb/March 1969
                        
Volume 19        Issue 1        Harry Smith Interview              April/May 1969
Volume 19        Issue 2        Sloop (Boat)                     July/Aug 1969
Volume 19        Issue 3        Indian on Horse                     Sept/Oct 1969
Volume 19        Issue 4        Song My April, 1968              Winter 1969/1970
Volume 19        Issue 5        Ramblin Jack Elliott              March/April 1970
Volume 19        Issue 6        Raimon                              1970
                        
                        
Volume 20        Issue 1        20th Anniversary Issue              Sept/Oct 1970
Volume 20        Issue 2        Art Rosenbaum Artwork              Nov/Dec 1970
Volume 20        Issue 3        Bernice Reagon                     Jan/Feb 1971
Volume 20        Issue 4        Bill Cheatham                     March/April 1971
Volume 20        Issue 5        Paul Siebel                     May/June 1971
Volume 20        Issue 6        Ry Cooder                     July/Aug 1971
                        
Volume 21         Issue 1        Hazel Dickens                     Sept/Oct 71
Volume 21         Issue 2        Folklore Center                     Jan/Feb 1972
Volume 21         Issue 3        Happy and Artie Tatum              March/April 1972
Volume 21         Issue 4        Kid w/ harp/fiddle              1972
Volume 21         Issue 5        Rev Gary Davis                     Sept/Oct 72
Volume 21         Issue 6        Jarrell and Cockerham              Nov/Dec 1972
                        
Volume 22        Issue 4        Joe Heaney                     Jan/Feb 1973
Volume 22        Issue 2        Bob Beers                     March/April 1973
Volume 22        Issue 3        Aunt Molly Jackson              May/June 1973
Volume 22        Issue 4        Teach In Issue                     July/Aug 1973
Volume 22        Issue 5        Chile (Fife)                     Sept/Oct 1973
Volume 22        Issue 6        Ray Fisher                     Jan/Feb 1974
                        
Volume 23        Issue 1        Sing Out Folk Festival            March/April 1974
Volume 23        Issue 2        Frankie Armstrong            May/June 1974
Volume 23        Issue 3        Larry Johnson                     July/Aug 1974
Volume 23        Issue 4        Drawing                             Sept/Oct 1974
Volume 23        Issue 5        New Orleans Mardi Gras            Nov/Dec 1974
Volume 23        Issue 6        Ralph Stanley                     Jan/Feb 1975
                        
Volume 24        Issue 1        Malvina Reynolds            March/April 1975
Volume 24        Issue 2        Nimrod Workman                    May/June 1975
Volume 24        Issue 3        Utah Phillips                    July/Aug 1975
Volume 24        Issue 4        Martin Carthy                    Sept/Oct 1975
Volume 24        Issue 5        Native American Music            Nov/Dec 1975
Volume 24        Issue 6        Black Music in America            Jan/Feb 1976
                        
Volume 25        Issue 1        25th Aniversary (Seeger)    May/June 1976
Volume 25        Issue 2        Sarah Ogan Gunning            July/Aug 1976
Volume 25        Issue 3        La Raza (Puerto Rico)            Sept/Oct 1976
Volume 25        Issue 4        Irish Musicians                    Nov/Dec 1976
Volume 25        Issue 5        Ellis Island Music            Jan/Feb 1977
Volume 25        Issue 6        Bai Konte                    March/April 1977
                        
Volume 26        Issue 1        Moe Asch                    May/June 1977
Volume 26        Issue 2        Wilma Lee Cooper            July/Aug 1976
Volume 26        Issue 3        Roosevelt Sykes                    Sept/Oct 1977
Volume 26        Issue 4        Andres Jimenez                    Nov/Dec 1977
Volume 26        Issue 5        Lillie West                    Jan/Feb 1978
Volume 26        Issue 6        Ed Larken                    March/April 1978
                        
Volume 27        Issue 1        Drawing (Kathie Abrams)            May/June 1978
Volume 27        Issue 2        Wassail                           July/Aug 1978
Volume 27        Issue 3        Leda Valladares                    May/June 1979
Volume 27        Issue 4        Nancy Lyon                    July/Aug 1979
Volume 27        Issue 5        Dave Van Ronk                    Sept/Oct 1979
Volume 27        Issue 6        Ardoin Family                     Nov/Dec 1979
                        
Volume 28        Issue 1        John Hartford                    Jan/Feb 1980
Volume 28        Issue 2        Peggy Seeger                    March/April 1980
Volume 28        Issue 3        30th Anniversary (Seeger)   May/June 1980
Volume 28        Issue 4        Klezmorim                    July/Aug 1980
Volume 28        Issue 5        Lee Hayes                    Sept/Oct 1980
Volume 28        Issue 6        Rose Maddux                    Nov/Dec 1980
                        
Volume 29        Issue 1        Django Reinhardt            Jan/Feb 1981
Volume 29        Issue 2        Festivals                    April/May/June 83
Volume 29        Issue 3        Trapezoid                    July-Sept 1983
Volume 29        Issue 4        Dewey Balfa/Tracey Schwartz Oct/Nov/Dec 83
                        
Volume 30        Issue 1        Hawaiian Music                    Jan/Feb/March 84
Volume 30        Issue 2        Sally Rogers                    Apr-May-June 1984
Volume 30        Issue 3        Tom Paxton                    July/Aug/Sept 84
Volume 30        Issue 4        Laskin/Robb                    Oct/Nov/Dec 84
                        
Volume 31        Issue 1        John Hammond                    Jan/Feb/March 85
Volume 31        Issue 2        Festival                    Apr/May/June 85
Volume 31        Issue 3        Taj Mahal                    July/Aug/Sept 85
Volume 31        Issue 4        Faith Petric                    Oct/Nov/Dec 85
                        
Volume 32        Issue 1        Queen Ida                    Winter 86
Volume 32        Issue 2        Nanci Griffith                    Fall 86
Volume 32        Issue 3        Howard Armstrong            Winter 87
Volume 32        Issue 4        Si Kahn                           Spring 87
                        
Volume 33        Issue 1        Richard Thompson            Fall 87
Volume 33        Issue 2        Ewan MacColl                    Winter 88
Volume 33        Issue 3        Bill Staines                    Spring 88
Volume 33        Issue 4        Cathy Fink & Marcy Marxer   Summer 88
                        
Volume 34        Issue 1        Eric Bogle                    Winter 89
Volume 34        Issue 2        Alistair Anderson            Spring 89
Volume 34        Issue 3        Christine Lavin                    Summer 89
Volume 34        Issue 4        Jerry Jeff Walker            Fall 89
                        
Volume 35        Issue 1        Katie Webster                    Spring 1990
Volume 35        Issue 2        David Bromberg                    Summer 1990
Volume 35        Issue 3        Michael Doucet                    Fall 1990
Volume 35        Issue 4        Walt Michael                    Winter 1991
                        
Volume 36        Issue 1        Conjunto Music                    Spring 1991
Volume 36        Issue 2        Odetta                           Aug/Sept/Oct 91
Volume 36        Issue 3        Songs of the Civil War            Nov/Dec 91, Jan 92
Volume 36        Issue 4                
                        
Volume 37        Issue 1        Arlo Guthrie                  May/June/July 92
Volume 37        Issue 2        Raffi                          Aug/Sept/Oct 92
Volume 37        Issue 3        Mahlathini                  Nov/Dec 92, Jan 93
Volume 37        Issue 4        Laurie Lewis                  Feb/March/April 93