It was recorded on 2 April 1972 at the Mar y Sol Pop Festival in Puerto Rico.

Previously available only on the 5CD+1DVD box-set From the Beginning (released in September 2007), this album was re-mastered from the original multitrack tapes.

Although the CD booklet states that this performance took place in "Vega Baja, San Juan", this is a production error.

Moreover, the festival actually took place in the municipality of Manatí which is very close to the borderline with Vega Baja.

Back in those days, everybody mistakenly knew the festival area as being inside Vega Baja instead of Manatí.