Last night's Supertramp concert at the Merriweather Post Pavilion was also the local installment of keyboard player Roger Hodgson's farewell. Hodgson, who alternates writing and singing duties with keyboardist-guitarist Rick Davies, is leaving the group at the end of the tour to pursue a solo career.

Having survived its English Art-Rock origins, Supertramp moved to America in the mid-'70s and developed a stateless brand of medium hard pop that's almost medicinal--it's sometimes hard to swallow but it's basically good for you. The sound is keyboard-oriented, with Davies and Hodgson enveloping their vocals with meticulous layers of glossiness.

The songs are essentially optimistic, though the confessional ones tend--as the genre is wont to do--to go on a bit too long and too much. Even an existential lament like "The Logical Song" assumes an upbeat persona with its insistently choppy arrangement.

In concert, as on record, Supertramp performs with tremendous attention to detail. As a result, renditions of favorites like "Bloody Well Right," "Dreamer" and the Cat Stevens-like "Give a Little Bit" were studio perfect, their precision seldom extended by visible or audible passion.

Throughout the night saxophonist John Helliwell split his energies skillfully--at times tenderizing the sound, at other times toughening it.

Supertramp plays safe but intriguing personal pop that smooths more feathers than it ruffles, easy-listening music with enough of a hard edge to keep it from being cloying.