Läther was originally conceived by Zappa as a 4-record box set that was rejected by his record company in early 1977. Most of the compositions were re-edited (sometimes with other arrangements) over the next two years into several albums (principally Live In New York, Studio Tan, Sleep Dirt, & Orchestral Favorites). The project was released only in 1996.
Tracks 5 to 8 on CD3 are bonus tracks to the original Läther box set.