The songs are released under GNU GPL, except :

SkyVibe-HighFrequency.ogg
--------------------
  Speedsound: CC-BY-SA v3.0
	modified by Constantin Pelikan

MayDayMayham.ogg
--------------------
  Alessandro Bottura: CC-SA v3.0
	modified by Constantin Pelikan

ChillCarrier-Druckverlust.ogg
--------------------
  Chill Carrier: CC-SA v3.0

g4m-fan-track.ogg
-----------------
  Paul Esra Martin, license: CC-SA v3.0

Boom_boom_boom.ogg
------------------
  Matt Thomas, license: GNU GPL v3 (or later)

kart_grand_prix.ogg
Win Theme
Lose Theme
--------------------
  Weirwood, license: CC

TheDeadRocks-EasyJob.ogg
TheDeadRocks-GreenSecretFromAmazonia.ogg
TheDeadRocks-OneMillionDollar.ogg
----------------
  The Dead Rocks, license: CC-BY-SA v3.0

dance_cleopatra.ogg
----------------
    ZamalSka, license: CC-BY-SA v3.0

Origin.ogg
----------------
    by Jahzzar, released under CC-BY-SA 3.0

Symphony #5
-----------
    Daniel Bautista
    license : CC-BY-SA 3.0

OnTheRiver.ogg
--------------
    by Bluepiano (http://www.jamendo.com/en/album/50394)
    with modifications by Magne Djupvik
    license : CC-BY-SA 3.0

Snowy.ogg
---------
    Music made by Chris Leutwyler (Krobonil)
    Released under CC-SA. (Creative Commons - Share Alike)
