The Red Hot Organization, whose philanthropic endeavors contribute to AIDS research, will celebrate its 10th anniversary with two additions to its acclaimed series of compilation tribute albums and free downloads of Red Hot tracks both new and old.

On March 13 the organization will release its 13th compilation, Red Hot + Indigo, a tribute to jazz composer/pianist/bandleader Duke Ellington that counts hip-hop combo the Roots, R&B crooner D'Angelo, singer Mary J. Blige, hip-hop duo Black Star, jazz trio Medeski Martin & Wood, post-rockers Tortoise, and electronic duo Propellerheads among its contributors. "We already tackled the others pillars of 20th-century music: [Antonio Carlos] Jobim with Red Hot + Rio, [George] Gershwin with Red Hot + Rhapsody, and Cole Porter with Red Hot + Blue," said Indigo producer Paul Heck. "So we wanted to pay tribute to Ellington as he was the last of those pillars standing." The album will be available exclusively through online retailer Amazon.com until early fall, when it will arrive at offline retail outlets.

Typically for the Red Hot series, the album features many first-time and unexpected collaborations: Black Star, bassist Ron Carter, and Hammond B-3 luminary John Patton join forces on "Money Jungle"; Medeski Martin & Wood's six tracks include collaborations with guitarist Kenny Burrell ("C Jam Blues"), Sex Mob trumpeter Steven Bernstein ("Haunted Nights"), and trombonist Art Baron ("Creole Love Call"); the Roots and D'Angelo - on keyboards - team for Ellington's "Caravan"; and Propellerheads and folk singer Martha Wainwright pair up for "Star-Crossed Lovers." The 17-track album also includes Tortoise's interpretation of "Didjeridoo," from Ellington's 1967 album Afro-Eurasian Eclipse, and Mary J. Blige's solo reading of "Do Nothin' Till You Hear From Me." Red Hot + Riot, the oft-delayed, hotly anticipated tribute to Nigerian Afro-beat rebel Fela Kuti, is due later this year. Macy Gray, D'Angelo, the Roots' ?uestlove, rapper Common, Dead Prez, trumpeter Roy Hargrove, and Fela's son Femi will appear on the tribute to Kuti, who died of AIDS-related complications in 1997.

Red Hot is also auctioning off 50 copies of Physiognomy, a collection of photographs taken by Rolling Stone photographer Mark Seliger, each containing a different pictured artist's autograph.

The organization also offers free, full-length MP3 downloads of select songs from the Red Hot catalog at Amazon.com, where listeners can also make contributions to the organization.

Visit redhot.org for more information on the Red Hot Organization.

Following is the track listing for Red Hot + Indigo: 1. Medeski Martin & Wood - "Acht O'Clock Rock"
2. Black Star/Ron Carter/John Patton - "Money Jungle"
3. Mary J. Blige - "Do Nothin' Till You Hear From Me"
4. Melky Sedeck - "Mood Indigo"
5. Les Nubians - "Come Sunday"
6. Medeski Martin & Wood/Art Baron - "Creole Love Call"
7. Propellerheads/Martha Wainwright - "Star-Crossed Lovers"
8. The Roots/D'Angelo - "Caravan"
9. Kenny Burrell/Medeski Martin & Wood - "C Jam Blues"
10. Don Byron/Dean Bowman - "Bli Blip"
11. Medeski Martin & Wood - "Mount Harissa"
12. Amel Larrieux - "Sophisticated Lady"
13. Kenny Burrell - "In a Sentimental Mood"
14. Terry Callier - "Satin Doll"
15. Medeski Martin & Wood/Steve Bernstein - "Haunted Nights"
16. Medeski Martin & Wood - "Blue Pepper (Dub)"
17. Tortoise - " Didjeridoo"

• Mary J. Blige
• Medeski Martin & Wood
• Duke Ellington