| O Katy O'Neil |
Irish | Girls Names |
| O Sole Mio |
Enrique Caruso |
| Ob la di, Ob la da |
The Beatles |
| Octopus's Garden |
The Beatles |
| Ode to Billy Joe |
Sinead O'Conner |
| Of Thee I Sing |
George Gershwin |
| Off We Go Into the Wild Blue Yonder |
Patriotic | United States Air Force Official Song |
| Oh Babe What Would You Say? |
Hurricane Smith, One Hit Wonders |
| Oh Darling |
The Beatles |
| Oh Girl |
The Spinners |
| Oh Happy Day |
Nick Cave & The Bad Seed |
| Oh! How I Hate To Get Up In the Morning |
Irving Berlin | War Songs |
| Oh Johnny, Oh Johnny, Oh! |
Al Jolson, Eddie Cantor, Sophie Tucker, Ziegfeld Follies |
| Oh Lonesome Me |
Don Gibson, Johnny Cash |
| Oh My Pa-pa |
Eddie Fisher |
| Oh Susanna |
Traditional |
| Oh Very Young |
Cat Stevens |
| Oh What a Beautiful Morning |
Rodgers and Hammerstein | Oklahoma |
| Oh! You Beautiful Doll! |
1911 |
| Okie from Muskogee |
Country |
| Oklahoma! |
Rodgers and Hammerstein | Oklahoma |
| Ol' Man River |
Jerome Kern | Showboat |
| Old Cape Cod |
Patti Page |
| Old Days |
Chicago |
| Old Devil Moon |
'Yip' Harburg | Broadway |
| Old McDonald |
Elvis Presley | Sing-a-Long |
| The Old Piano Roll Blues |
Cy Coben, Cass Daley, Lawrence Cook, Hoagy Carmichael |
| Old Songs |
Barry Manilow |
| Old Time Rock and Roll |
Bob Seger and the Silver Bullet Band |
| Ole Buttermilk Sky |
Hoagy Carmichael | Kay Kaiser, Paul Weston |
| On a Clear Day You Can See Forever |
Lerner and Loewe | Barbra Streisand |
| On a Little Street In Singapore |
Frank Sinatra | Manhattan Transfer |
| On and On |
Stephen Bishop |
| On Broadway |
George Benson, Lieber and Stoller, The Drifters |
| On the Atchison, Topeka & the Santa Fe |
Johnny Mercer | Harry Warren |
| On the Good Ship Lollipop |
Shirley Temple, Rudy Valee |
| On the Road Again |
Country |
| On the Street Where You Live |
Nat 'King' Cole | Lerner and Loewe |
| On the Wings of Love |
Jeffrey Osborne |
| On This Night of a Thousand Stars |
Andrew Lloyd-Webber | Broadway |
| On Top of Old Smokey |
Folk | Song |
| On Top of Spaghetti |
Sing-a-Long |
| Once In a Lifetime |
Broadway | Sammy Davis Jr. |
| Once In Love With Amy |
Frank Leosser |
| Once Upon a Dream (Sleeping Beauty) |
Tchaikovsky |
| Once Upon a Time |
Broadway | All American |
| One |
Broadway | A Chorus Line |
| One Angry Dwarf and 200 Solemn Faces |
Ben Folds Five |
| One Boy |
| Bye Bye Birdie |
| One Day In Your Life |
Michael Jackson |
| One Fine Day |
Carole King | The Carpenters |
| One For My Baby |
Frank Sinatra | Harold Arlen |
| One Hand, One Heart |
West Side Story | Broadway |
| One Headlight |
The Wallflowers (1997) |
| One In a Million You |
Larry Graham |
| One is the Loneliest Number |
Three Dog Night, Paul Williams |
| One Less Bell To Answer |
Burt Bacharach | Fifth Dimension |
| One Moment in Time |
Whitney Houston |
| One Note Samba (Samba de Um Nota So) |
Ella Fitzgerald |
| One Of These Nights |
The Eagles |
| One Of Those Songs |
Shirley Bassey, Liza Minnelli |
| One of Us |
Joan Osborne |
| The One That You Love |
Air Supply |
| One Tin Soldier |
Coven |
| One-Two-Three |
Gloria Estefan |
| One Week |
Barenaked Ladies |
| Only Sixteen |
Dr. Hook |
| Only the Good Die Young |
Billy Joel |
| Only Yesterday |
The Carpenters |
| Only You |
The Platters |
| O-o-h Child |
Dee Dee Sharp |
| Ooh Baby |
Linda Ronstadt |
| Oops! I Did It Again |
Britney Spears |
| Open A New Window |
Mame | Broadway |
| Open Arms |
Journey, Mariah Carey |
| Operator |
Manhattan Transfer |
| Operator (That's Not the Way it Feels) |
Jim Croce |
| Orange Colored Sky |
Nat 'King' Cole | Natalie Cole |
| Original Rags |
Instrumental |
| Our Day Will Come |
The Carpenters | Frankie Valli |
| Our House |
Crosby, Stills and Nash |
| Our Love Is Here To Stay |
George Gershwin | Nat 'King' Cole |
| Out of My Dreams |
Rodgers and Hammerstein | Broadway |
| Over the Rainbow |
Harold Arlen | Yip Harburg |
| Over There |
George M. Cohan | Patriotic |
| Over You |
Gary Pucket and the Union Gap |
| Overjoyed |
Stevie Wonder |