SDI & Quartet: Sega System 16 Collection: Original Soundtrack is an album containing music from the Sega System 16 games SDI: Strategic Defense Initiative and Quartet. It also contains tracks from the Sega Master System port of Quartet (Double Target).
A new arrange track for each game is included at the end of the album: a remix of "System Down" from SDI by original composer Katsuhiro Hayashi and a medley of Quartet's themes performed by [H.].
The album was released at the same time as Sega Ages 2500 Series Vol. 21: SDI & Quartet: Sega System 16 Collection.
| 3. Satellite Attack (2:34)
| 8. We are Desirous of Peace (1:12)
| 10. Illusion (Ranking) (0:13)
| 11. Miami Samba Machine (0:13)
| 18. Miami Samba Machine (Rap Nashi Ver.) (0:15)
| JP: Miami Samba Machine (Rap なし Ver.)
| EN: Miami Samba Machine (No Rap Ver.)
| 32. SDI Remix 2005 (4:58)
| 33. Quartet Medley 2005 (6:56)
| Album, JP