This excellent compilation contains 2 cd's. The first cd contains 26 tracks with a duration of 77 minutes, while the 2nd cd contains 26 tracks with a duration of almost 70 minutes. Along with the cd's, you also receive a very well annotated 28 page booklet written by Mr. Alec Palao, which contains many rare photos & pictures of both the recording artists, as well as pics of the 45's and L.P.'s in this very fine collection. When one remembers the Mainstream record label, you can usually recall that just The Amboy Dukes and Big Brother and The Holding Company led by famed vocalist Janis Joplin, recorded on that label. In fact, Big Brother only recorded their first L.P. on the Mainstream label before they moved to Columbia Records. Well, this collection reveals a large amount of other very fine groups who recorded for the Mainstream Label. This collection contains the strongest album tracks, some very good singles-only cuts, and some rare mono mixes and unreleased material, which together form a rich potpourri of Psychedelic Pop, Garage-Rock and overall some heavy-duty freakiness. Some of the other groups who stand-out in this collection are Fever Tree, The Jelly Bean Bandits, The Tangerine Zoo, The Tiffany Shade, The Stone Circus, The Bohemian Vendetta, The Orphans, The Art Of Lovin', The Sixpentz. Freeport, and Maxx. All 52 tracks in this collection are at least good with the majority being very good to excellent! If you were to try to track down the songs in this collection, you would be very fortunate to find them. If you Were able to, you would be dishing out at least several Thousand Dollars! Some tunes are flat-out psychedelic, while many of the others start out as more pop-orientated, but in the middle of the tune you will hear a fuzz-drenched guitar solo, or some swirling organ sound right out of 1968. The remastered sound of these tunes is excellent and it sounds like they were taken from the original analog masters, which only adds to the excellent sound. All-In-All, any fan of 60's Pop-Psych will find this collection a true delight! MOST HIGHLY RECOMMENDED!! SMRZ!!