And now (as they say) for something completely different. Rhythm And Blues, like all other art forms, did not exist in a vacuum. There were many contemporaneous influences on it, as well as those from out of the past. This is a list, by no means exhaustive, of R&B songs which had their origins in either musicals (usually on Broadway) or movies (which were not necessarily musicals). Bet you'll be surprised at some of the entries.
NOTE: This is not intended to be a complete listing of all groups that made a particular song. It's just a representative sample.
A Lovely Way To Spend An Evening
By: Harold Adamson & Jimmy McHugh
From: the movie "Higher And Higher" (1943) (Frank Sinatra's first movie)
Angels - Grand 121 - 1954
Ink Spots - Decca 18583 - 1944
Spaniels - Unreleased Vee-Jay - 1957
Again
By: Dorcas Cochran & Lionel Newman
From: the movie "Road House" (1949) - introduced by Ida Lupino
4 Chords - Sittin' In With 516 - 1948
5 Crowns - Unreleased Rainbow - 1952
5 Satins - Ember LP - 1957
Universals - Mark-X 7004 - 1957
At Last
By: Mack Gordon & Harry Warren
From: the movie "Sun Valley Serenade" (1941) - Ray Eberle with the Glenn Miller Ork
Richard Berry & Dreamers - Flair 1052 - 1954
Mello-Tones - Aires 1015 - 1954
Begin The Beguine
By: Cole Porter
From: the play "Jubilee" (1935) - a 1938 Artie Shaw hit
Flamingos - End LP - 1959
Ravens - Mercury 5800 - Feb 1952
Bewitched, Bothered And Bewildered
By: Rogers & Hart
From: the play "Pal Joey" (1940; Gene Kelly was Joey) - a 1950 Doris Day hit
Platters - Mercury LP - Ca. 1958
Blueberry Hill
By: Al Lewis, Larry Stock & Vincent Rose
From: the movie "The Singing Hill" (1941) - introduced by Gene Autry
Red Caps - Mercury 8146 - Jul 1949
By The Light Of The Silvery Moon
By: Gus Edwards & Edward Madden
From: the play "School Boys And Girls" (1909)
Etta James - Modern 1022 - 1957
Little Richard - Specialty 660 - 1959 (recorded Oct 56)
Olympics - Arvee 5020 - 1960
Can't Help Lovin' That Gal Of Mine
By: Oscar Hammerstein & Jerome Kern
From: the play "Showboat" (1927) - a hit for Helen Morgan
Hide-A-Ways - Ronni 1000 - 1955
Leaders - Glory 243 - 1956
Count Your Blessings
By: Irving Berlin
From: the movie "White Christmas" 1954 - introduced by Bing Crosby and Rosemary Clooney
Orioles - Jubilee 5172 - 1954
Did You Ever See A Dream Walking
By: Mack Gordon & Harris Revel
From: the movie "Sitting Pretty" (1933) - introduced by Jack Haley
Ink Spots - From a 1935 radio broadcast (on an 1980 LP)
Do You Know What It Means To Miss New Orleans
By: Edgar Leslie & Louis Alter
From: the movie "New Orleans" (1947) - introduced by Billie Holiday and Louis Armstrong
4 Vagabonds - Apollo 1039 - 1947
Embraceable You
By: George & Ira Gershwin
From: the play "Girl Crazy" (1930) - sung by Ginger Rogers
Jumping Jacks - Bruce 115 - 1954
Solitaires - Old Town 1066 - 1959
Exactly Like You
By: Dorothy Fields & Jimmy McHugh
From: the play "Lew Leslie's International Revue" (1930)
Barons - Decca 29293 - 1954
Basin Street Boys - Exclusive 247 - 1953
For You
By: Al Dubin & Joseph A. Burke
From: the movie "Holy Terror" (1930)
Ravens - National 9034 - 1947
Hands Across The Table
By: Mitchell Parish & Jean DeLettre
From: the play "Continental Follies" (1934) - a 1934 Lucienne Boyer hit
Cadets - Modern 1024 - 1957
Ray-O-Vacs - Decca 48260 - 1951
Velours - Onyx 515 - 1957
Heart And Soul
By: Frank Loesser & Hoagy Carmichael)
From: the movie "A Song Is Born" (1938)
4 Buddies - Savoy 817 - 1951
Del Vikings - Mercury LP - 1957
Spaniels - Vee-Jay 301 - 1958
Cleftones - Gee 1064 - 1961
Hold Me
By: Art Hickman & Ben Black
From: the play "Ziegfield Follies of 1920"
5 Keys - Aladdin 3136 - 1952
Larks - Apollo 1194 - 1952
The House I Live In
By: Louis Allen & Earl Robinson
From: the play "Let Freedom Ring" (1942) - introduced by Earl Robinson; Popularized in a 1945 Oscar-winning short by Frank Sinatra
4 Notes - International 455 - 46
Ravens - National 9073 - 1949
I Can't Get Started With You
By: Ira Gershwin & Vernon Duke
From: the play "Ziegfield Follies of 1936" - introduced by Bob Hope & Eve Arden
Charioteers - Columbia 37915 - 11/47
Fat Man Humphries & 4 Notes (Crows) - Jubilee 5085 - 1952
I Couldn't Sleep A Wink Last Night
By: Harold Adamson & Jimmy McHugh
From: the movie "Higher And Higher" (1943)
Imperials - End LP - 1961
Mello-Moods - Red Robin 104 - 1952
I Cover The Waterfront
By: Edward Heyman & John Green
From: the movie "I Cover The Waterfront" (1933) - the song was ordered for the movie, but it wasn't ready in time. When finally finished, it became a big hit for Ben Bernie and was put into subsequent prints of the film.
Cats 'N' Jammers - Mercury 2003 - 1946
Orioles - Jubilee 5120 - 1953 (recorded 1948)
I Had The Craziest Dream
By: Mack Gordon & Harry Warren
From: the movie "Springtime In The Rockies" (1942); by Helen Forrest (with the Harry James Ork.)
4 Vagabonds - Bluebird 30-0810 - 1943
I Love Paris
By: Cole Porter
From: the play "Can Can" (1953)
Chris Powell & Blue Flames - Grand 112 - 1954 (I Love Paris Mambo)
Robins - Spark 113 - 1955
I May Be Wrong But I Think You're Wonderful
By: Harry Ruskin & Henry Sullivan
From: the play "Murray Anderson's Almanac" (1929)
Orioles - Unreleased Jubilee - recorded 1951
I Only Have Eyes For You
By: Al Dubin & Harry Warren
From: the play "Dames" (1934) - sung by Dick Powell
Flamingos - End 1046 - 1959
Sonny Til & Edna McGriff - Jubilee 5090 - 1952
Swallows - King 4533 - 1952
I Wonder Who's Kissing Her Now
By: Will Hough & Frank Adams
From: the play "The Prince Of Tonight" (1909) - a 1947 #2 Perry Como hit
4 Vagabonds - Apollo 1055 - 1947
If You Were The Only Girl In The World
By: Clifford Gray & Nat Ayer
From: the movie "The Vagabond Lover" (1929) - sung by Rudy Vallee
Castelles - Grand 105 - 1954
Larks - unreleased Lloyds - 1954
I'll Always Be In Love With You
By: Bud Green, Herman Ruby, Sam Stept
From: the movie "Stepping High" (1928)
5 Keys - Aladdin Unreleased; recorded 1952
Danleers - Epic 9421 - 1960
Hurricanes - King 5018 - 1957
Ravens - Jubilee 5237 - 1956
Ray-O-Vacs - Coleman 100 - 1949
I'll Be Seeing You
By: Irving Kahal & Sammy Fain
From: the play "Right This Way" (1938) - introduced by Tamara
5 Satins - Ember 1061 - 1960
Crescendos - Atlantic 2014 - 1959 (recorded 1956)
Hollywood Flames - Ebb 153 - 1958
I've Got You Under My Skin
By: Cole Porter
From: the movie "Born To Dance" (1936) - introduced by Virginia Bruce
Ravens - Mercury 70413 - 1954
Jeepers Creepers
By: Johnny Mercer & Harry Warren
From: the movie "Going Places" (1938) - introduced by Dick Powell and Louis Armstrong
Dells - Vee-Jay 292 - 1958
Let's Call The Whole Thing Off
By: George & Ira Gershwin
From: the movie "Shall We Dance" (1937) - introduced by Fred Astaire and Ginger Rogers
Ink Spots - Decca 1251 - 1937
Lonesome Road
By: Gene Austin & Nathaniel Shilkret
From: the movie "Show Boat" (1929) - interpolated into the movie (that is, it was put into the movie, although it hadn't been in the show)
4 Tunes - RCA 50-0042 - 1949
Dominoes - King 1364 - 1954
Fashions - V-Tone 202 - 1959
Ravens - Mercury 70330 - 1954
Tune Weavers - Casa Grande 101 - 1959
Love Walked In
By: George & Ira Gershwin
From: the movie "The Goldwyn Follies" (1938) - introduced by Kenny Baker
Flamingos - End 1055 - 1959
Dinah Washington - Mercury 71696 - 1960
Mam'selle
By: Mack Gordon & Edmund Goulding
From: the Somerset Maugham movie "The Razor's Edge" (1946) - a 1947 Sinatra hit
Ravens - Okeh 6888 - 1952
Marie
By: Irving Berlin
From: the movie "My Awakening" (1928)
4 Tunes - Jubilee 5128 - 1953
Fidelitys - Sir 271 - 1959
Guy Brothers - States 101 - 1952
Ravens - Rendition 5001 - 1951
Maybe
By: George & Ira Gershwin
From: the play "Oh, Kay" (1926) - introduced by Getrude Lawrence
Ink Spots - Decca 3258 - 1940
More Than You Know
By: Billy Rose & Edward Eliscu & Vincent Youmans
From: the play "Great Day" (1929)
Johnny Moore's Three Blazers - Modern 20-599 - 1948
Gene Mumford - Columbia 41233 - 1958
Platters - Mercury 71986 - 1962
Scamps - Modern Music 20-512 - 1947
My Mother's Eyes
By: L. Wolf Gilbert & Abel Baer
From: the play "Lucky Boy" (1929) - introduced by George Jessel
4 Buddies - Savoy 888 - 1953
Clovers - Poplar LP - 1958
Soft Tones - Sampson 103 - 1954
Ol' Man River
By: Oscar Hammerstein & Jermome Kern
From: the play "Showboat" (1927) - introduced by Jules Bledsoe in the play (and Paul Robeson in the subsequent movie)
Gems - Drexel 904 - 1954
Ravens - National 9035 - 1947
Skylarks - Verve 10082 - 1957
Tune Weavers - Casa Grande 4037 - 1957
100 Years From Today
By: Victor Young
From: the play "Blackbirds of 1933" - a 1933 hit for Ethel Waters
4 Shades Of Rhythm - Vitacoustic 1005 - 1952
Jones Brothers - Majestic 1038 - 1946
Spaniels - Vee-Jay 328 - 1959
Over The Rainbow
By: Yip Harburg & Harold Arlen
From: the movie "Wizard Of Oz" (1939) - introduced by Judy Garland
Chanters - Deluxe 6177 - 1958
Checkers - King 4179 - 1954
Del Chords - Kane 25593 - 1959
Del Vikings - Luniverse 106 - 1957
Dominoes - King 1502 - 1955
Echos - Specialty 601 - 1957
Moroccos - United 193 - 1955
Vibrations - Checker 1002 - 1961
Pennies From Heaven
By: Johnny Burke & Arthur Johnson
From: the movie "Pennies From Heaven" (1936) - introduced by Bing Crosby
Clovers - Poplar LP - 1958
Matadors - Sue 700 - 1957
Treniers - Brunswick 55033 - 1957
Poor Butterfly
By: John Golden & Raymond Hubble
From: the play "The Big Show" (1916) - introduced by Haru Onuki (who, in spite of his Japanese-sounding name, was Chinese)
3 Barons (3 Riffs) - Recorded for Savoy in November 1944
Platters - Mercury LP - 1962
Red Sails In The Sunset
By: Jimmy Kennedy & Hugh Williams
From: the play "Provincetown Follies" (1935) - a 1935 Bing Crosby hit
5 Keys - Aladdin 3127 - 1952
Balladeers - Jubilee 5021 - 1950
Johnnie & Joe - J&S 1701 - 1959
Platters - Mercury 71656 - 1960
Spaniels - Unreleased Vee-Jay - 1959
River Stay Away From My Door
By: Mort Dixon & Harry Woods
From: the play "Mum's The Word" (1931) - introduced by Jimmy Savo
Dixieaires - Continental 1227 - 1948
Syncopaters - National 9095 - 1949
Secret Love
By: Paul Francis Webster & Sammy Fain
From: the movie "Calamity Jane" (1953) - introduced by Doris Day (it won an Oscar)
Moonglows - Chance 1152 - 1954
Orioles - Jubilee 5137 - 1954
Jimmy Ricks - Felsted 8560 - 1959
September In The Rain
By: Al Dubin & Harry Warren
From: the movie "Stars Over Broadway" (1935) introduced by James Melton
Al Hibbler - Decca LP - 1956
Royal Jokers - Hi-Q 5004 - 1957
September Song
By: Maxwell Anderson & Kurt Weill
From: the play "Knickerbocker Holiday" (1938) - a 1939 Walter Houston hit
Dominoes - Decca 30514 - 1957
Flamingos - Unreleased Chance - 1954
Platters - Mercury LP - 1961
Ravens - National 9053 - 1948
Ravens - Mercury 70307 - 1954
Sheik Of Araby
By: Harry Smith & Francis Wheeler
From: the play "Make It Snappy" (1921)
Colts - Antler 4003 - 1957
Slap That Bass
By: George & Ira Gershwin
From: the movie "Shall We Dance" (1937) - introduced by Fred Astaire
Ink Spots - Decca 1251 - 1937
Smoke Gets In Your Eyes
By: Otto Harbach & Jerome Kern
From: the play "Roberta" (1933) - introduced by Tamara
Richard Barrett - MGM 12616 - 1958
Platters - Mercury 71383
So Strange
By: Cole Porter, with help from Adam Jackson (Jackson claimed he wrote the song on a subway; he "fixed up" the lyrics a bit.)
From: "Kiss Me Kate" (1948 as "So In Love") - a 1949 Patti Page hit
Jesters - Winley 218 - 1957
Someone To Watch Over Me
By: George & Ira Gershwin
From: the play "Oh, Kay" (1926) - a 1927 Gertrude Lawrence hit
Platters - Mercury LP - 1958
Something I Dreamed Last Night
By: Herb Magidson & Jack Yellin
From: the play "George White Scandals of 1939" introduced by Ella Logan
Delta Rhythm Boys - Elektra LP 138 - ca. 1959
Stormy Weather
By: Ted Koehler & Harlold Arlen
From: introduced by Ethel Waters in a 1933 Cotton Club Revue
5 Bars - Money 224 - 1956
5 Sharps - Jubilee 5104 - 1952
Golden Gate Quartet - Bluebird 8579 - 1940
Leaders - Glory 235 - 1955
Spaniels - Vee-Jay 290 - 1958
Jackie Wilson - Brunswick LP - 1961
Stranger In Paradise
By: Robert Wright & George Forrest
From: the play "Kismet" (1953) - the melody was adapted from Borodin's Polevetsian Dances - a 1953 Tony Bennett hit (it actually became a hit before the show opened). Introduced in the show by Richard Kiley.
Solitaires - Unreleased Old Town - recorded Jan 1954
Summertime
By: DuBose Heyward & George Gershwin
From: the play "Porgy & Bess" (1935) - a 1936 Billie Holliday hit
Jesse Belvin - Modern 1025 - 1957
Chantels - Carlton 569 - 1962
Sam Cooke - Keen 34013 - 1957
Little Esther - Federal 12063 - 1952
Midnighters - King LP - 1961
Platters - Mercury LP - 1961
Ravens - National 9038 - 1947
Jimmy Ricks - Signature LP - 1960
Sweet Sue, Just You
By: Will Harris & Victor Young (written in 1928)
From: the movie "Rhythm Parade" (1942) - sung by the Mills Brothers
Crows - Rama 50 - 1954
Gondoliers - Specialty - 1956
Mills Brothers - Brunswick 6330 - 1932
Swing High, Swing Low
By: Ralph Freed & Burton Lane
From: the movie "Artists & Models" (1937) - introduced by Dorothy Lamour
Ink Spots - Decca 1236 - 1937
Tea For Two
By: Irving Caesar & Vincent Youmans
From: the play "No No Nannette" (1925) - a 1925 Marion Harris hit
Ravens - Unreleased National, Ca. 1949
That Old Gang Of Mine
By: Billy Rose & Mort Dixon & Ray Henderson
From: the play "Ziegfield Follies of 1923"
4 Vagabonds - Apollo 1076 - 1947
These Foolish Things
By: Holt Marvell & Jack Strachey & Harry Link
From: "Spread It Abroad" (a 1935 British musical) - introduced by Madge Elliott and Cyrill Ritchard - a 1936 Benny Goodman hit
5 Keys - Aladdin 3190 - 1953
5 Satins - Cub 9077 - 1960
Dominoes - Federal 12129 - 1953
Clyde McPhatter - Mercury LP - 1960
Three Coins In The Fountain
By: Sammy Cahn & Jule Styne
From: the movie of the same name (1954) - sung by Frank Sinatra over the credits
Dominoes - King 1364 - 1954
Wagon Wheels
By: Billy Hill & Peter DeRose
From: the play "Ziegfield Follies of 1934" - introduced by Everett Marshall
Blue Notes - Josie 823 - 1957
Platters - Mercury LP - Ca. 1956
Ravens - Mercury 8259 - 1951
Turks (Hollywood Flames) - Cash 1042 - 1956
The Way You Look Tonight
By: Dorothy FIelds & Jerome Kern
From: the movie "Swing Time" (1936) - introduced by Fred Astaire
Jaguars - R-Dell 11 - 1956
With Plenty Of Money And You
By: Al Dubin & Harry Warren
From: the movie "Gold Diggers Of 1937" - introduced by Dick Powell
Ink Spots - Decca 1154 - 1937
Without A Song
By: Billy Rose & Edward Eliscu
From: the play "Great Day" (1929) - a 1930 Paul Whiteman hit
Checkers - King 4675 - 1953
Malcolm Dodd - MGM 13025 - 1961
Isley Brothers - RCA 47-7657 - 1959
Ravens - Mercury 70240 - 1953
You'll Never Walk Alone
By: Rodgers & Hammerstein
From: the play "Carousel" (1945) - introduced by Christine Johnson
Flamingos - End LP - 1960
Roy Hamilton - Epic 9015 - 1954
Imperials - Great Lakes 1212 - 1954
Zing! Went The Strings Of My Heart
By: James Hanley
From: the play "Thumbs Up" (1935) - introduced by Hal Leroy
Coasters - Atco 6116 - 1958
Furys - Mack IV 112 - 1963