OK, this is way overkill, but that's how I do things: obsessively. Here is your musical year 1946, in a fast shuffle.

Check in Library of Congress material recorded then. Somewhat sparse, because activity was slow getting started after the war, and appropriations were slow to be granted. But there should be some material field-recorded in 1946. Unfortunately my copy of Library of Congress: A Check-list of Folk Songs (Arno) ends at 1940...no help there.

See also studio recordings made by Moe Asch for Asch and Disc 78s of 1946. Dating is difficult! Among these were Lomax's recordings of Texas Gladden and Hobart Smith for Disc, but they may be 1947, not sure. Some great stuff including the first recording of "Railroad Bill" to reach the North. Also Cousin Emmy for Decca, great stuff! but I think that's 1947 too.

Asch/Disc had various Woody Guthrie, Lead Belly and other sides perhaps (Somewhere on the web I think there's a WG discography; check that). Some of the original Stinson material came from the same source.

Lornell and Wolfe Lead Belly biography has LB quite active in 1946, recording such songs as Yellow Gal, Borrow Love and Go, Eagle Rag Rock and Good Morning Blues with Bunk Johnson (jazz!) plus sides with Terry, McGhee, Guthrie and others: Diggin' My Potatoes, Defense Blues, Easy Rider, Pigmeat, Alabama Bound, Ham and Eggs, Stew Ball, Gray Goose, Midnight Special, Green Corn, Fiddler's Dram, Irene, The Gallis Pole, Bourgeois Blues, etc.

But you'd have to check deeper to find out whether this material was new in that year, or had been recorded previously.

In addition to the Seeger album mentioned above, Pete and Betty Sanders were recording a seven-song "Bawdy Ballads and Real Sad Songs" for Charter Records during 1946-7, but the record evidently did not come out till '47. Includes Molly Brannigan, Young to Marry, Hey Donald, The Soldier Laddy, Wedding and Bedding, In the Evening, East Virginia.

Carl Sandburg and others may have been recording during that year: Musicraft, maybe Decca. John Jacob Niles perhaps.

Bradley Kincaid recorded "Legend of the Robin's Red Breast," "Footprints in the Snow," "The Fatal Derby Day" and other material for Majestic c. 1945; it was issued by various companies c. 1946.

Bascom Lamar Lunsford was recording for the Library of Congress in 1946. "I Wish I Was a Mole In the Ground," "On a Bright and Summer's Morning,""Death of Queen Jane," etc.

THINGS NOT SO FOLKY BUT MAYBE OF INTEREST. I realize you probably aren't looking for these, but I just got carried away:

Blues. A few of the bluesmen recording in '46:
Big Bill Broonzy: I Can Fix It, Old Man Blue, I Can't Write, What Can I Do
Gabriel Brown Black Jack Blues, You Ain't No Good, etc.
Doctor Clayton: Root Doctor Blues,. Midnight Rambler, Hold That Train Conductor (Clayton died that year)
Arthur "Big Boy" Crudup: So Glad You're Mine, That's All Right (Elvis picked it up later).
Walter Davis: My Friends Don't Know Me, Please Remember Me, etc.
Champion Jack Dupree: Rum Cola Blues, She Makes Good Jelly, FDR Blues, etc.
Lowell Fulson: Don't Be So Evil, Black Widow Spider Blues
Jazz Gillum: Reckless Rider Blues, Roll Dem Bones, etc.
Lightnin' Hopkins: Can't Do Like You Used to Do, West Coast Blues, etc.
Brownie McGhee: Goin' Down Slow, Rock Me Mama, Night Time Is the Right Time, etc.
Memphis Minnie: Killer Diller, Moaning Blues, Lean Meat Won't Fry, etc.
Memphis Slim: Slim's Boogie, Little Mary, Grinder Man Blues, etc.
Tampa Red: Let's Try It Again, Crying Won't Help You, etc.
Montana Taylor: Low Down Boogie, Toot Your Whistle, etc.
T-Bone Walker: No Worry Blues, Bobby Sox Blues, etc.
Sonny Boy Williamson (the original, not Rice Miller): Mean Old Highway, Hoodoo Hoodoo, etc.

Pop music 1946 included among many others: Chiquita Banana, Five Minutes More, I'm a Big Girl Now, I'm a Lonely Little Petunia (In An Onion Patch), It's a Pity to Say Goodnight, Managua Nicaragua, Ole Buttermilk Sky, Old Devil Moon, Pickle in the Middle (And the Mustard on Top), Tenderly, the classic To Each His Own, plus Aloha Oe? and Ev'rybody Got a Laughin' Place? (not sure about these two).

Spaeth lists among 1946's top songs It Couldn't Be True, It's a Good Day, I'd Be Lost Without You, Oh, Why, Oh, Why Did I Ever Leave Wyoming?, ONe-zy Two-zy, Route 66!, Seems Like Old Times, and Mel Torme's The Christmas Song with several others.

Country music 1946: Doin' What Comes Natcherly, You Call Everybody Darlin'.

King Records was busy recording then little-known country acts in 1946. Check the King List for Delmore Brothers in particular. Also Grandpa Jones was recording with the Delmore Bros and Merle Travis as the Brown's Ferry Four, including Just a Little Talk with Jesus, I'll Fly Away, Everybody Will Be Happy Over There, Old Camp Meeting, Over in Glory Land, On the Jericho Road. Grandpa made a 1946 album with Merle including Eight More Miles to Louisville, Darling Won't You Love Me Now, Are There Tears Behind Your Smiles, Get Things Ready For Me, Ma, Ridin' On That Train and Heart Stealin' Mama. He also recorded Rex Griffin's Alimony Trouble that year.

Lot of great stuff in 1947, like "Smoke, Smoke, Smoke." Too bad it came too late.

Nuff already.