In 1969, Yes recorded their eponymous debut album, to be followed by Time And A Word, on which his band mates JonAnderson and Chris Squire wanted the backing of an orchestra.
Alvarado has coached since 1988, winning five Los Angeles city championships and guiding such players as major-leaguers Garret Anderson and Jon Garland.
The Tykes fell behind to a Steven Fletcher strike but hit back 60 seconds later through Jon Macken and then in first-half stoppage time with a spectacular strike from Anderson De Silva.
Barnsley levelled a minute later when Jon Macken scored from close range and they were ahead at half-time thanks to Anderson da Silva's 25-yard screamer.