i'll take a second to address the question of whether MP3/AAC compression is noticeable when compared to the lossless original:
on a decent quality playback system, compression (even at the highest possible bit rate) IS noticeable with musical content that contains subtle details such as the bowing of a stringed instrument in symphonic music, or the hiss of a ride cymbal in jazz. most people simply don't know that they're missing something because they've never heard a comparison, or they aren't intimately familiar with the instruments in the recording.
lossy audio compression is great for certain things, but it fails to accurately capture music as it's intended to be heard.
on a decent quality playback system, compression (even at the highest possible bit rate) IS noticeable with musical content that contains subtle details such as the bowing of a stringed instrument in symphonic music, or the hiss of a ride cymbal in jazz. most people simply don't know that they're missing something because they've never heard a comparison, or they aren't intimately familiar with the instruments in the recording.
lossy audio compression is great for certain things, but it fails to accurately capture music as it's intended to be heard.