On a deep spice journey, you don't need music. You might want to listen to what's happening in the trip.
Of course, you can listen to music, but it won't really matter if you are deep enough.
A lighter changa mix (3:1 or even 4:1) is a different story. I roll joints when I do these kinds of sessions. That way I have more control over dosage and can go as deep as I want but still back off and take it slower if I wish. I like to listen to music during this kind of changa sessions. Listen to what you really love and know well. Instrumental is probably better. Lyrics can color the trip in unpleasant ways, in my experience.
I listened to As Falls Wichita, So Falls Wichita Falls by Pat Metheny & Lyle Mays one time, and met some interesting entities. I was sitting outside in autumn and enjoying my experience, and I thought: "This isn't like lsd or other psychs where music is drastically effected." Then I took another hit. Suddenly there were all these little guys. They looked like the spark from a bic lighter. They said: "Oh yeah? Watch what we can do to music."
I was listening to the song Ozark, which I know very well. I've listened to it hundreds of times. With no distortion or artifacts, these little sparks joyfully deconstructed and re-arranged the song. There were no psychedelic effects. No crazy warping or echoes. The sounds of the instruments were untouched. They sounded normal, but they were being moved around in the most incredible ways. When the song ended, the entities spoke up: "Again!."
I obliged them. I took another hit and listened in amazement as they did it again, with endlessly, impossibly creative variations. They insisted that I play it again and again. I did.
Then the most wonderful thing happened. The sounds around me, outside of my headphones, began to merge with the sounds of the recording. Piano notes merged seamlessly with and then became the wind. Traffic zoomed by, born out of guitar chords. Moving away in impossibly dense and rational dopplers of harmonic perfection. The percussion turned into the crisp texture of dry leaves and rattling branches.
Then, I merged with all of it and became the weather and the music.
The entities thanked me and asked if I liked what they could do with music. I was in tears. I was so grateful for what they had shown me. Now, whenever I listen to the album while smoking changa, they come back.
While I obviously recommend the album, it's more important that you find something that you absolutely love and listen to that. I'd only suggest this if you go into the trip with the intention of listening deeply. If you just want a backdrop, it's probably not worth worrying too much about what you put on, as long as it's something that doesn't make you uncomfortable.
I hope this helps.