Having posted the #1 songs up to 1930, and the comment above that "folk" songs ended soon after, I feel sort of obligated to post a little further so people can decide for themselves whether it's really all over and done.

Note that the songs that made #1 on the charts, as I've posted, may give a rather different view of the mood and musical tastes than a survey of the whole group of songs that "made the charts" in a given year.

1931
1. 1/17 7 The Peanut Vendor ... Don Azpiazu
2. 2/14 2 Just A Gigolo .. . Ted Lewis
3. 3/21 3 By The River St. Marie .. .Guy Lombardo
4. 4/04 1 Minnie The Moocher .. . Cab Calloway
5. 4/18 1 Star Dust... Isham Jones
6. 4/25 4 Dream A Little Dream Of Me... Wayne King
7. 5/16 3 Out Of Nowhere .. . Bing Crosby
8. 6/06 3 (There Ought To Be A) Moonlight Saving Time ...Guy Lombardo
9. 6/27 2 Just One More Chance .. .Bing Crosby
10. 7/11 3 I Found A Million-Dollar Baby (In A Five-And-Ten-Cent Store)... Fred Waring's Pennsylvanians
11. 8/08 3 At Your Command .. . Bing Crosby
12. 8/22 6 Sweet And Lovely... Gus Arnheim
13. 10/03 2 When The Moon Comes Over The Mountain... Kate Smith
14. 10/17 7 Good Night, Sweetheart...Wayne King
15. 12/05 2 Goodnight, Sweetheart...Guy Lombardo
16. 12/19 4 Tiger Rag ... Mills Brothers

1932
1. 1/16 2 River, Stay 'Way From My Door ... Kate Smith with Guy Lombardo
2. 1/30 2 Dinah ... Bing Crosby & Mills Brothers
3. 2/13 3 All Of Me... Paul Whiteman
4. 3/05 2 All Of Me ... Louis Armstrong
5. 3/19 2 Too Many Tears .. . Guy Lombardo
6. 4/02 6 Paradise ... Leo Reisman
7. 5/14 3 Paradise ... Guy Lombardo
8. 6/04 2 Lullaby Of The Leaves .. .George Olsen
9. 6/18 10 n A Shanty In Old Shanty Town ... Ted Lewis
10. 8/27 5 We Just Couldn't Say Goodbye ... Guy Lombardo
11. 10/01 2 Say It Isn't So ... George Olsen
12. 10/15 6 Please... Bing Crosby
13. 11/26 2 Brother, Can You Spare A Dime? ... Bing Crosby
14. 12/10 2 Brother, Can Ton Spare A Dime? ... Rudy Vallee
15. 12/24 10 Night And Day ... Fred Astaire with Leo Reisman

1933
1. 3/04 4 You're Getting To Be A Habit With Me ... Bing Crosby
2. 4/01 3 Forty-Second Street... Don Bestor
3. 4/22 8 Stormy Weather .. . Leo Reisman featuring Harold Arlen
4. 6/17 3 Stormy Weather ... Ethel Waters
5. 7/08 2 Shadow Waltz ... Bing Crosby
6. 7/22 4 Lazybones ... Ted Lewis
7. 8/19 5 Love Is The Sweetest Thing... Ray Noble
8. 9/23 9 The Last Round-Up ...George Olsen
9. 11/04 3 The Last Round-Up .. . Guy Lombardo
10. 12/16 3 Did You Ever See A Dream Walking? ... Eddy Duchin

1934
1. 1/06 3 The Old Spinning Wheel...Ray Noble
2. 1/20 6 Smoke Gets In Your Eyes .. .Paul Whiteman
3. 2/24 5 Let's Fall In Love ... Eddy Duchin
4. 3/03 1 My Little Grass Shack In Kealakekua, Hawaii .. .Ted Fio Rito
5. 3/31 2 The Carioca .. . Enric Madriguera
6. 4/07 1 Wagon Wheels .. . Paul Whiteman
7. 4/14 5 Little Dutch Mill... Bing Crosby
8. 5/12 5 Cocktails For Two ... Duke Ellington
9. 6/09 5 I'll String Along With You... Ted Fio Rito
10. 7/07 1 Moon Glow ... Benny Goodman
11. 7/14 5 The Very Thought Of You... Ray Noble
12. 7/14 2 All I Do Is Dream Of You...Jan Garber
13. 8/18 6 Love In Bloom .. . Bing Crosby
14. 9/15 4 I Saw Stars ... Freddy Martin
15. 10/20 4 One Night Of Love ... Grace Moore
16. 10/27 2 The Continental (You Kiss While You're Dancing)...Leo Reisman
17. 11/10 4 Stars Fell On Alabama ...Guy Lombardo
18. 12/08 7 June In January ... Bing Crosby
19. 12/08 3 Stay As Sweet As Yon Are... Jimmie Grier
20. 12/29 2 The Object Of My Affection... Jimmie Grier

1935
1. 1/12 7 Isle Of Capri... Ray Noble
2. 1/26 3 Blue Moon ... Glen Gray
3. 1/26 2 The Object Of My Affection... Boswell Sisters
4. 3/23 4 Lovely To Look At.. . Eddy Duchin
5. 4/13 2 It's Easy To Remember...Bing Crosby
6. 4/20 1 Soon... Bing Crosby
7. 5/04 3 I Won't Dance... Eddy Duchin
8. 5/04 2 Lullaby Of Broadway...Dorsey Brothers Orchestra
9. 5/18 2 What's The Reason (I'm Not Pleasin' You)... Guy Lombardo
10. 6/01 2 Life Is A Song .. . Ruth Etting
11. 6/15 4 When I Grow Too Old To Dream ... Glen Gray
12. 6/22 4 She's A Latin From Manhattan ... Victor Young
13. 6/29 3 Chasing Shadows .. . Dorsey Brothers Orchestra
14. 7/13 3 In A Little Gypsy Tea Room... Bob Crosby
15. 7/20 2 Let's Swing It.. . Ray Noble
16. 8/03 1 Rhythm Is Our Business .. .Jimmie Lunceford
17. 8/10 11 Cheek To Cheek... Fred Astaire
18. 8/10 1 Paris In The Spring .. . Ray Noble
19. 8/17 1 And Then Some... Ozzie Nelson
20. 8/24 2 East Of The Sun (And West Of The Moon)... Tom Coakley
21. 9/07 3 I'm In The Mood For Love... Little Jack Little
22. 10/19 3 Truckin'... Fats Waller
23. 11/02 3 You Are My Lucky Star ...Eddy Duchin
24. 11/30 4 Red Sails In The Sunset..Guy Lombardo
25. 12/21 2 Red Sails In The Sunset...Bing Crosby
26. 12/21 1 On Treasure Island...Tommy Dorsey
27. 12/28 2 A Little Bit Independent...Fats Waller

1936
1. 1/04 5 The Music Goes Round And Round ... Tommy Dorsey
2. 1/04 3 The Music Goes Round And Round ... Riley-Farley Orchestra
3. 2/01 3 Moon Over Miami... Eddy Duchin
4. 2/08 6 Alone ... Tommy Dorsey
5. 2/29 2 A Beautiful Lady In Blue ...Jan Garber
6. 3/14 6 Goody-Goody... Benny Goodman
7. 3/21 1 Lights Out... Eddy Duchin
8. 4/04 1 I'm Putting All My Eggs InOne Basket... Fred Astaire
9. 4/11 2 It's Been So Long... Benny Goodman
10. 5/02 2 Lost... Guy Lombardo
11. 5/09 3 A Melody From The Sky...Jan Garber
12. 5/23 1 You... Tommy Dorsey
13. 5/30 6 The Glory Of Love .. . Benny Goodman
14. 6/06 4 Is It True What They Say About Dixie? .. . Jimmy Dorsey
15. 6/06 1 All My Life... Fats Waller
16. 7/11 2 There's A Small Hotel...Hal Kemp
17. 7/18 2 Take My Heart... Eddy Duchin
18. 7/25 4 It's A Sin To Tell A Lie ...Fats Waller
19. 8/01 2 These Foolish Things Remind Me Of You .. .Benny Goodman
20. 8/15 2 When I'm With Ton .. . Hal Kemp
21. 8/22 2 Until The Real Thing Comes Along ... Andy Kirk
22. 8/29 4 Did I Remember?... Shep Fields
23. 9/05 5 A Fine Romance... Fred Astaire
24. 10/03 6 The Way Tou Look To-night... Fred Astaire
25. 10/10 2 When Did Tou Leave Heaven?... Guy Lombardo
26. 11/14 2 Tou Turned The Tables On Me... Benny Goodman
27. 11/28 10 Pennies From Heaven...Bing Crosby
28. 12/05 1 I'll Sing Tou A Thousand Love Songs.,. Eddy Duchin
29. 12/12 2 In The Chapel In The Moonlight... Shep Fields

1937
1. 1/02 2 It's De-Lovely.... Eddy Duchin
2. 2/06 4 Goodnight, My Love .. Benny Goodman
3. 2/20 4 This Tear's Kisses... Hal Kemp
4. 2/20 1 With Plenty Of Money And You... Henry Busse
5. 2/27 3 This Tear's Kisses .. .Benny Goodman
6. 3/27 2 Marie... Tommy Dorsey
7. 4/03 5 Boo Hoo... Guy Lombardo
8. 4/17 10 Sweet Leilani... Bing Crosby
9. 4/24 1 Too Marvelous For Words ... Bing Crosby
31. 12/11 1
10. 5/01 1 They Can't Take That Away From Me ... Fred Astaire
11. 5/15 3 Carelessly... Teddy Wilson featuring Billie Holiday
12. 6/05 4 September In The Rain ... GuyLombardo
13. 7/03 5 It Looks Like Rain In Cherry Blossom Lane ... Guy Lombardo
14. 7/03 2 The Merry-Go-Round Broke Down ... Russ Morgan
15. 7/17 2 The Merry-Go-Round Broke Down ... Shep Fields
16. 7/24 1 Where Or When... Hal Kemp
17. 7/31 2 Smarty ... Fats Waller Gone With The Wind .. .Horace Heidt
18. 7/31 1 A Sailboat In The Moonlight...GuyLombardo
19. 8/07 3 Satan Takes A Holiday .. .Tommy Dorsey
20. 8/21 3 Whispers In The Dark .. .Bob Crosby
21. 9/04 4 The Big Apple .. . Tommy Dorsey's Clam Bake Seven
22. 9/11 2 So Rare ... Guy Lombardo
23. 9/11 1 The Moon Got In My Eyes ... Bing Crosby
24. 9/25 4 That Old Feeling .. . Shep Fields
25. 10/09 4 You Can't Stop Me From Dreaming ... Teddy Wilson
26. 10/16 2 Remember Me? .. . Bing Crosby
27. 11/06 3 Vieni, Vieni ... Rudy Vallee
28. 11/20 1 Once In A While .. . Tommy Dorsey
29. 11/27 7 The Dipsy Doodle .. . Tommy Dorsey Bob White
30. 11/27 6 (Whatcha Gonna Swing Tonight?)... Bing Crosby & Connee Boswell

1938
1. 1/01 1 Nice Work If You Can Get It ... Fred Astaire
2. 1/15 2 Rosalie ... Sammy Kaye
3. 1/22 5 Bei Mir Bist Du Schoen .. . Andrews Sisters
4. 1/29 1 You're A Sweetheart... Dolly Dawn
5. 2/26 4 Thanks For The Memory ... Shep Fields
6. 3/19 6 Ti-Pi-Pin ... Hoarce Heidt
7. 3/19 5 Don't Be That Way .. .Benny Goodman
8. 4/23 3 I Let A Song Go Out Of My Heart ... Duke Ellington
9. 5/07 2 Please Be Kind ... Red Norvo
10. 5/14 3 Love Walked In ... Sammy Kaye
11. 5/21 4 Cry, Baby, Cry ... Larry Clinton
12. 5/28 3 Cathedral In The Pines .. .Shep Fields
13. 6/11 1 I Let A Song Go Out Of My Heart ... Benny Goodman
14. 6/18 4 Says My Heart ... Red Norvo
15. 6/25 10 A-Tisket, A-Tasket... Ella Fitzgerald with Chick Webb
16. 7/16 6 Music, Maestro, Please...Tommy Dorsey
17. 9/17 2 Change Partners... Fred Astaire
18. 9/24 2 Alexander's Ragtime Band... Bing Crosby & Connee Boswell
19. 10/01 8 My Reverie ... Larry Clinton
20. 10/01 4 I've Got A Pocketful Of Dreams ... Bing Crosby
21. 10/15 2 Change Partners .. . Jimmy Dorsey
22. 10/29 2 I've Got A Pocketful Of Dreams ... Russ Morgan
23. 10/29 1 Heart And Soul... Larry Clinton
24. 11/05 6 Begin The Beguine .. . Artie Shaw
25. 12/17 2 Two Sleepy People .. . Fats Waller
26. 12/31 2 You Must Have Been A Beautiful Baby ... Bing Crosby
27. 12/31 2 I Won't Tell A Soul (I Love You)... Andy Kirk

1939
1. 1/07 2 They Say ... Artie Shaw
2. 1/14 5 Jeepers Creepers .. . Al Donohue
3 1/14 1 Thanks For Ev'rything .. .Artie Shaw
4 2/04 1 The Umbrella Man .. . Kay Kyser
5 2/ll 9 Deep Purple .. . Larry Clinton
6. 3/18 1 Penny Serenade .. . Guy Lombardo
7. 4/22 2 Heaven Can Wait... Glen Gray
8. 5/06 1 Our Love ... Tommy Dorsey
9. 5/13 5 And The Angels Sing .. .Benny Goodman
10. 5/20 2 Three Little Fishies .. . Kay Kyser
11. 6/03 4 Beer Barrel Polka .. . Will Glahe
12. 6/10 4 Wishing (Will Make It So)...Glenn Miller
13. 7/08 4 Stairway To The Stars .. .Glenn Miller
14. 8/12 4 Moon Love ... Glenn Miller
15. 8/12 2 Sunrise Serenade . .. Glen Gray
16. 9/09 7 Over The Rainbow .. . Glenn Miller
17. 9/09 3 The Man With The Mandolin... Glenn Miller
18. 9/30 1 Blue Orchids ... Glenn Miller
19. 10/21 1 Day In, Day Out... Bob Crosby
20. 11/04 5 South Of The Border (Down Mexico Way)... Shep Fields
21. 11/11 1 Address Unknown .. . Ink Spots
22. 11/25 8 Scatter-Brain ... Frankie Masters

1940
1. 1/27 2 All The Things Ton Are ...Tommy Dorsey
2. 2/03 5 Careless ... Glenn Miller
3. 2/10 12 In The Mood ... Glenn Miller
4. 2/24 1 Indian Summer ... Tommy Dorsey
5. 3/16 1 Darn That Dream ... Benny Goodman
6. 3/30 5 When You Wish Upon A Star ... Glenn Miller
7. 5/04 9 Tuxedo Junction ... Glenn Miller
8. 5/04 7 The Woodpecker Song ...Glenn Miller
9. 6/22 3 Imagination ... Glenn Miller
10. 7/10 2 Make-Believe Island...Mitchell Ayres
11. 7/20 1 Fools Rush In (Where Angels Fear To Tread)...Glenn Miller
12. 7/27 12 I'll Never Smile Again ...Tommy Dorsey
13. 8/24 2 Where Was I? ... Charlie Barnet
14. 9/07 1 The Breeze And I... Jimmy Dorsey
15. 9/14 4 Sierra Sue ... Bing Crosby
16. 10/19 9 Only Forever ... Bing Crosby
17. 11/23 1 Blueberry Hill... Glenn Miller
18.11/28 3 Ferryboat Serenade ...Andrews Sisters
19. 11/30 4 Trade Winds ... Bing Crosby
20. 12/21 13 Frenesi ... Artie Shaw

John