I don't find any infos about this budget 4cd box.If you want buy some from legendary tango (jazz) man Piazzolla, this is small info: only 2nd disc is taken form studio recordings.It is from late 60's.First disc includes concert in Roma 1972 (Piazzolla's Nonet)Third disc includes concert in Milano 1984(quintet)Fourth disc is from 1976 - it is electric Piazzolla.But sound is good. And music too.