Complete the game under the indicated difficulty setting to unlock the corresponding song in the Jukebox option.
Beach Bossa: Captain
Brazilicious: Captain.
Contortion: Lieutenant.
Dance Of The Unknown: Lieutenant.
Dark In Your Heart: Captain.
Gnostec: Lieutenant.
Infiltrator: Lieutenant.
Insertion Suite: Lieutenant.
KGM: Lieutenant.
SOCOM II Finale: Captain.
Tari Tari: Lieutenant.