- 4-5-6 by Foxy Brown
- 4-ever by Nb Ridaz
- 4.16 AM by Before the Dawn
- 4.w.d. (low Ratio) by Jethro Tull
- 4/20 by Pearl Jam
- 40 by U2
- 40 & A Blunt by Das Efx
- 40 Acres And My Props by Showbiz & A.g.
- 40 Below by Spineshank
- 40 Days 40 Fights by Badly Drawn Boy
- 40 Days And 40 Nights by Tim McGraw
- 40 Days, 40 Fights by Badly Drawn Boy
- 40 ft by Franz Ferdinand
- 40 Hour Week by Alabama
- 40 Island by Noreaga
- 40 Kinds Of Sadness by Ryan Cabrera
- 40 Miles From the Sun by Bush
- 40 Miles Of Bad Road by Dead Moon
- 40 oz by D12
- 40 Oz Quartet Part I by Tha Alkaholiks
- 40 Oz Quartet Part II by Tha Alkaholiks
- 40 Past Midnight by Ocean Colour Scene
- 40 secondi di niente by Verdena
- 40 Years by Counting Crows
- 40,000k by Jesus And Mary Chain
- 40-40 Home by Haircut 100
- 400 degreez by Juvenile
- 400 Years by Bob Marley
- 401 Kill by Rise Against
- 405 Friday's by Defari
- 409 by Beach Boys
- 409 by Ice-t
- 409 in Your Coffeemaker by Green Day
- 41:19 by Public Enemy
- 42nd Street by Diana Krall
- 43 by Mushroomhead
- 4321 by DMX
- 433 (Hypothetical Situation) by Sinch
- 44 Caliber Love Letter by Alexisonfire
- 44 Killers by Three 6 Mafia
- 44 Killerz by Three 6 Mafia
- 44 Robbers by Laika
- 44 Stories by Rosanne Cash
- 45 by Anything Box
- 45 by Shinedown
- 45 Seconds Of Ecstasy by Meat Loaf
- 48 Hour Parole by Hollies
- 48 Hours by Blue System
- 48 Hours by Clash, The
- 48 Hours by Vengaboys
- 4:30 am by Obie Bermúdez
- 4:35 In The Morning by Saint Etienne
- 4am by Our Lady Peace
- 4am Conversation by Boo Radleys, The
- 4give Me. by Holy Hustla
- 4st 7lb by Manic Street Preachers
- 4th Chamber by Genius
- 4th Floor Freaks by Souls Of Mischief
- 4th Movement by Gino Vanelli
- 4th Of July by Ani DiFranco
