Kenny Loggins and Jim Messina's combined talents reached a kind of apotheosis in concert, all based on the same relationship they'd had in the studio -- Loggins' songwriting and singing, supported by Messina's performing and his long experience with Poco, came to a head on the tour leading up to this concert album, recorded at two East Coast venues in March of 1973 and at Winterland in San Francisco the following month. After a gorgeous yet subdued introduction by Loggins as a solo performer on a handful of numbers, Messina and the band take the stage and loft the proceedings into a bracing mix of folk- and country-rock. And they break those boundaries, soaring into psychedelic territory on the 21-minute "Vahevala," which took up all of side three on the original LP. One would think that everything after that would be anti-climactic, but all involved are just as sharp on the fourth side of more modestly proportioned gems. As praiseworthy as the duo's playing and singing is, one must also credit the rhythm section of Larry Simms (bass) and Merle Brigante (drums), and Al Garth (violin, horns) and Jon Clarke (flute, horns) for their performances. This is a live album that hits on all cylinders, and its only flaw, if there is one, is actually a byproduct of one of its virtues: On Stage was recorded so early in their history that it only really represents the songs off the duo's first two albums (Full Sail wouldn't be out until six months after these shows). Otherwise, it could easily have copped the "best-of" designation in substance, if not actual name.