I don't use FLAC, I use M4A/ALAC so the files are still lossless and the rest are MP3s. The songs that are lossless were converted from WAVE from the master source so there's no loss in degradation. It's just the best source quality I could find with minimal fan tinkering with the tracks like fan edits like Gho5t etc. iTunes is the reason why I use ALAC, you can just convert it to FLAC with no loss in quality if you wish, just make sure the bit depth is set to 16-bit and 44.1 kHz. A program called, XRecode II is free and converts every audio file format with the latest codecs.