I bumped into this fine netlabel on monochromatica.com. Test Tube is in fact a netlabel with music from artists sharing their music to the community licensed under a creative commons license. This implies you can copy and distribute this music for free but cannot use it for commercial purposes. Sounds like a sweet deal you say? Indeed it is. And in fact this system works very fine and gives the chance to a lot of artists to spread their music in a group way fashion. Union makes force! Test Tube harbors about a hundred artists which you can check out here all individually. I would say enough music to mine for the whole summer. I picked up some songs of their latest released artists which should get you started. Praise to netlabels!
tube'|174 - Mannequin Blood - Concussion Dreamer
tube'|173 - Out Level - sx guitar EP
tube'|172 - mon0 - Multifidus
tube'|171 - Surtsey - Symphony No. 1 For Strings: Antarctica