There's something familiar about many of Legacy's new entries in their ongoing The Essential series hitting stores in April and May.

Of the four double-disc compilations - one for prog-rock masters Blue Öyster Cult, one apiece for country stars Alan Jackson and Brooks & Dunn and one for pop chanteuse Mariah Carey - three have already been reissued under different names. The country ones are repackages of each performer's latest hits set (Jackson's 2010 contract-closing 34 Number One Hits and Brooks & Dunn's 2009 #1s...and Then Some, released ahead of the duo's farewell tour), while Mariah's set came out in 2001 as Greatest Hits, once the singer left Columbia for a brief, disastrous run with Virgin. (That set has already been reissued as The Essential Mariah Carey in Europe as of last year.)

And while the new set, The Essential Blue Öyster Cult, provides new fans with a healthy look at their lengthy career beyond just the cowbell-heavy antics of "(Don't Fear) the Reaper" (not to mention expanding heavily upon the 2003 single-disc set of the same name), none of the material here is new. The compilation slightly resembles a less-rarity-packed version of 1995's Workshop of the Telescopes (one track of which, the cover of "Born to Be Wild," appears here).

All of these sets are out April 17 except the Mariah Carey set, available May 8. Hit the jump for full details on all of them.

Blue Öyster Cult, The Essential Blue Öyster Cult (Columbia/Legacy 88691 93633-2, 2012)

Disc 1

1. Cities on Flame with Rock and Roll
2. Before the Kiss, a Redcap
3. Stairway to the Stars
4. Transmaniacon MC
5. Buck's Boogie (Live)
6. The Red and the Black
7. O.D.'d on Life Itself
8. 7 Screaming Diz-Busters
9. Career of Evil
10. Flaming Telepaths
11. Astronomy
12. Hot Rails to Hell
13. Harvester of Eyes
14. M.E. 262
15. Born to Be Wild

Disc 2

1. (Don't Fear) the Reaper
2. This Ain't the Summer of Love
3. E.T.I. (Extra-Terrestrial Intelligence) (Live)
4. Godzilla
5. I Love the Night
6. Goin' Through the Motions
7. In Thee
8. Black Blade
9. The Marshall Plan
10. Veteran of the Psychic Wars
11. Joan Crawford
12. Burnin' for You
13. Roadhouse Blues (Live)
14. Shooting Shark
15. Take Me Away
16. Dancin' in the Ruins

Disc 1, Tracks 1-4 from Blue Öyster Cult (CBS, 1972)
Disc 1, Track 5 from On Your Feet or On Your Knees (Columbia, 1975)
Disc 1, Tracks 6-8 and 12 from Tyranny and Mutation (CBS, 1973)
Disc 1, Tracks 9-11 and 13-14 from Secret Treaties (CBS, 1974)
Disc 1, Track 14 is an outtake first released on Workshop of the Telescopes (Columbia, 1995)
Disc 2, Tracks 1-2 from Agents of Fortune (Columbia, 1975)
Disc 2, Track 3 from Some Enchanted Evening (Columbia, 1978)
Disc 2, Tracks 4-6 from Spectres (Columbia, 1977)
Disc 2, Track 7 from Mirrors (Columbia, 1979)
Disc 2, Tracks 8-9 from Cultösaurus Erectus (Columbia, 1980)
Disc 2, Tracks 10-12 from Fire of Unknown Origin (Columbia, 1981)
Disc 2, Track 13 from Extraterrestrial Live (Columbia, 1982)
Disc 2, Tracks 14-15 from The Revolution by Night (Columbia, 1983)
Disc 2, Track 16 from Club Ninja (Columbia, 1985)

Alan Jackson, The Essential Alan Jackson (Arista Nashville/Legacy 88691 96797-2, 2012 - originally released as 34 Number Ones - Arista Nashville 88697 78681-2, 2010)

Disc 1

1. Ring of Fire
2. Here in the Real World
3. Wanted
4. Chasin' That Neon Rainbow
5. I'd Love You All Over Again
6. Don't Rock That Jukebox
7. Someday
8. Dallas
9. Midnight in Montgomery
10. Love's Got a Hold on You
11. She's Got the Rhythm (and I Got the Blues)
12. Tonight I Climbed the Wall
13. Chattahoochee
14. (Who Says) You Can't Have It All
15. Summertime Blues
16. Livin' on Love
17. Gone Country
18. I Don't Even Know Your Name
19. Tall, Tall Trees

Disc 2

1. As She's Walking Away - Zac Brown Band featuring Alan Jackson
2. Look at Me
3. I'll Try
4. Home
5. Little Bitty
6. Who's Cheatin' Who
7. There Goes
8. Between the Devil and Me
9. Right on the Money
10. It Must Be Love
11. Where I Come From
12. Where Were You (When the World Stopped Turning)
13. Drive (for Daddy Gene)
14. It's Five O'Clock Somewhere - Alan Jackson and Jimmy Buffett
15. Remember When
16. Small Town Southern Man
17. Good Time
18. Country Boy

Disc 1, Track 1 is a new track exclusive to original version of this compilation
Disc 1, Tracks 2-5 from Here in the Real World (Arista Nashville, 1989)
Disc 1, Tracks 6-10 from Don't Rock the Jukebox (Arista Nashville, 1991)
Disc 1, Tracks 11-14 from A Lot About Livin' (and a Little 'Bout Love) (Arista Nashville, 1992)
Disc 1, Tracks 15-18 from Who I Am (Arista Nashville, 1994)
Disc 1, Track 19 and Disc 2, Track 2 from The Greatest Hits Collection (Arista Nashville, 1995)
Disc 2, Track 1 from You Get What You Give (Atlantic/Bigger Picture/Southern Ground, 2010)
Disc 2, Track 2 from Billy: The Early Years - Original Motion Picture Soundtrack (Arista Nashville, 2008)
Disc 2, Track 4 was the B-side to "Blue Blooded Woman" (Arista Nashville, 1989)
Disc 2, Tracks 5-8 from Everything I Love (Arista Nashville, 1996)
Disc 2, Track 9 from High Mileage (Arista Nashville, 1998)
Disc 2, Track 10 from Under the Influence (Arista Nashville, 1999)
Disc 2, Track 11 from When Somebody Loves You (Arista Nashville, 2000)
Disc 2, Tracks 12-13 from Drive (Arista Nashville, 2002)
Disc 2, Tracks 14-15 from Greatest Hits Volume II (Arista Nashville, 2003)
Disc 2, Tracks 16-18 from Good Time (Arista Nashville, 2008)

Brooks & Dunn, The Essential Brooks & Dunn (Arista Nashville/Legacy 88691 96799-2, 2012 - originally released as #1s...and Then Some - Arista Nashville 88697 49922-2, 2009)

Disc 1

1. Honky Tonk Stomp (feat. Billy Gibbons)
2. Brand New Man
3. Ain't Nothing 'Bout You
4. Hillbilly Deluxe
5. How Long Gone
6. She's Not the Cheatin' Kind
7. A Man This Lonely
8. Rock My World (Little Country Girl)
9. Red Dirt Road
10. The Long Goodbye
11. You're Gonna Miss Me When I'm Gone
12. If You See Him/If You See Her (feat. Reba McEntire)
13. She Used to Be Mine
14. That Ain't No Way to Go
15. Boot Scootin' Boogie

Disc 2

1. Indian Summer
2. Play Something Country
3. My Next Broken Heart
4. Cowgirls Don't Cry (feat. Reba McEntire)
5. Lost and Found
6. Little Miss Honky Tonk
7. It's Getting Better All the Time
8. We'll Burn That Bridge
9. He's Got You
10. Only in America
11. I Am That Man
12. Husbands and Wives
13. Neon Moon
14. My Maria
15. Believe

Disc 1, Track 1 and Disc 2, Track 1 are new tracks exclusive to original version of this compilation
Disc 1, Tracks 2 and 15 and Disc 2, Tracks 3, 5 and 13 from Brand New Man (Arista Nashville, 1991)
Disc 1, Tracks 3 and 10 and Disc 2, Track 10 from Steers and Stripes (Arista Nashville, 2001)
Disc 1, Track 4 and Disc 2, Tracks 2 and 15 from Hillbilly Deluxe (Arista Nashville, 2005)
Disc 1, Tracks 5 and 12 and Disc 2, Track 12 from If You See Her (Arista Nashville, 1998)
Disc 1, Tracks 6 and 11 and Disc 2, Tracks 6 from Waitin' on Sundown (Arista Nashville, 1994)
Disc 1, Track 7 and Disc 2, Tracks 11 and 14 from Borderline (Arista Nashville, 1996)
Disc 1, Tracks 8 and 13-14 and Disc 2, Track 8 from Hard Workin' Man (Arista Nashville, 1993)
Disc 1, Track 9 from Red Dirt Road (Arista Nashville, 2003)
Disc 2, Track 4 from Cowboy Town (Arista Nashville, 2007)
Disc 2, Track 7 from The Greatest Hits Collection II (Arista Nashville, 2004)
Disc 2, Track 9 from The Greatest Hits Collection (Arista Nashville, 1997)

Mariah Carey, The Essential Mariah Carey (Columbia/Legacy 88691 96808-2, 2012 - originally released as Greatest Hits - Columbia C2K 85960, 2001 and re-released in Europe as Columbia/Legacy 88697 83267-2, 2011)

Disc 1

1. Vision of Love
2. Love Takes Time
3. Someday
4. I Don't Wanna Cry
5. Emotions
6. Can't Let It Go
7. Make It Happen
8. I'll Be There (Live)
9. Dreamlover
10. Hero
11. Without You
12. Anytime You Need a Friend
13. Endless Love - Luther Vandross & Mariah Carey
14. Fantasy

Disc 2

1. One Sweet Day - Mariah Carey & Boyz II Men
2. Always Be My Baby
3. Forever
4. Underneath the Stars
5. Honey
6. Butterfly
7. My All
8. Sweetheart
9. When You Believe - Mariah Carey & Whitney Houston
10. I Still Believe
11. Heartbreaker (feat. Jay-Z)
12. Thank God I Found You
13. Can't Take That Away (Mariah's Theme)
14. All I Want for Christmas is You (So So Def Remix featuring Jermaine Dupri and Lil Bow Wow)

Disc 1, Tracks 1-4 from Mariah Carey (Columbia, 1990)
Disc 1, Tracks 5-7 from Emotions (Columbia, 1991)
Disc 1, Track 8 from MTV Unplugged EP (Columbia, 1992)
Disc 1, Tracks 9-12 from Music Box (Columbia, 1993)
Disc 1, Track 13 from Songs (Epic, 1994)
Disc 1, Tracks 14 and Disc 2, Tracks 1-4 from Daydream (Columbia, 1995)
Disc 2, Tracks 5-7 from Butterfly (Columbia, 1997)
Disc 2, Tracks 8 and 10 from #1s (Columbia, 1998)
Disc 2, Track 9 from The Prince of Egypt: Music from the Original Motion Picture (DreamWorks, 1998)
Disc 2, Tracks 11-13 from Rainbow (Columbia, 1999)
Original version of Disc 2, Track 14 from Merry Christmas (Columbia, 1994). Previously released on Sony Music Entertainment CD single SRCS 2425 (JP), 2000.