Rock’s Energetic Dream Theater Knows How to Rouse Audience

Often weighed down by complex compositions, lofty themes and heavy-duty displays of musicianship, progressive rock can be daunting. The genre’s better practitioners understand that these dense elements need to be balanced with concrete themes (melodic and lyrical) and spontaneous energy--musical wisdom Dream Theater demonstrated during its performance at the Galaxy Theatre in Santa Ana on Wednesday.

The set--composed of material from the New York group’s current album, “Metropolis Pt. 2: Scenes From a Memory,” in its entirety--shifted between sweeping melodic stretches that spurred the fervent, near-capacity crowd to sing-alongs and bouts of fierce, inspired jamming. The songs, which ranged from relatively simple ballads to multipartite epics, all revolved around a detailed story about a man who discovers he is the reincarnation of a murdered girl. The concept may be intriguing, but the most engaging aspect of Dream Theater’s performance was the vibrant, down-to-earth enthusiasm the musicians channeled into the music.

Opener Spock’s Beard was also committed to the prog-rock ethos, but proved almost too eclectic for its own good, swerving from folky acoustic stretches to Latin-inflected grooves, flat-out rockers and melodramatic ballads. Yet the quintet tackled it all with a giddy glee that frequently proved more fascinating than the music itself.

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* Dream Theater plays tonight and Saturday at the Palace, 1735 N. Vine St., 8 p.m. 27.50. (213) 462-3000.