The formats are:
snr = #01a527db
sns = #01eef63a

Ealayer3 can decode and encode these.

The adventure music can be replaced:
www.metacafe.com/w/10489901
I don´t know how to add new ones whitout replacing an existent song yet. But you guys can help in this way

Is easy to convert a MP3 file to SNR using the ealayer3. Is the same to make custom songs for the Sims 3. Google it

I made it
This is the proof:
http://www.mediafire.com/download.php?pd80haungbq5fik
Replaces the song of Stunning Dance level 3.
Now, i can change any game sound in the adventure editor.

Best regards from S2

Hi. I have been working for the music of the game.
Spore doesn´t work with ogg format. Never did it.
The sound files are located in #021407EE.
Listen this song that i have extracted:
http://www.goear.com/listen/877cdd4/spore-galaxy-maxis