It may be impossible to isolate just what it is about Mose Allison's music that appeals to disparate audiences, but his wry, honest and nearly always opinionated lyrics have to be near the top of the list.

Thursday night at Blues Alley, where he performs through Sunday, the pianist offered numerous examples of his crafty songwriting. For all his clever wordplay, though, his best songs have always offered a lot more than a chuckle, and last night even his laconic delivery couldn't conceal the provocative questions posed by tunes like "If You Only Knew" and "How Much Truth." If anything, the questions were more intriguing for being understated.

In contrast to his leisurely vocals, Allison is a forceful pianist, fond of cascading right-hand runs and of rumbling choruses. Along with drummer Mike Smith and bassist Drew Gress, he charged several tunes with a racing momentum. Along the way he also paused to retrieve and refresh some gentle tunes, songs well worth hearing again, from the distant past.

Stryper

Stryper comes from California and plays heavy metal. Loudness comes from Japan and also plays heavy metal. Thursday night at Merriweather Post Pavilion both bands played their music at sound levels that threatened to cause cranial damage.

Unfortunately, most of Loudness' performance was lost in the din. Lead singer Minoru Niihara's vocals were overwhelmed in the thunderous clamor; only a faint hint of melody could be heard occasionally. When that happened, ;owever, the music was surprisingly accessible.

As the headlining band, Stryper shelled the audience with most of the songs from its latest album, "To Hell With the Devil." The group, which is labeled a Christian band, has earned its hard-rock stripes by combining almost lilting melodies to many of its crushing chords.

There were a fair share of rock-spectacle moments, but songs like "To Hell With the Devil," with its anthemic chorus, and "Rockin' the World" were fierce enough to overcome their derivative nature.