Solos (Songlines) is a superb solo piano album by pianist-composer-improvisers Wayne Horvitz and Robin Holcomb. Both beguile the ears by breathtakingly fusing the hermetic, astringent squiggles of Schoenberg's piano music with the lonesome sound of Shaker hymns.

The disc begins with Holcomb's lullaby "Reno," whose deceptively simple sing-song melody immediately detours into interrogative, almost oblique, fragments of notes like a vivid childhood memory clinging to only two or three details--the intense purple of a shag carpet or the scent of an old wooden attic. From Horvitz's "Improvisation #1" which skitters and stutters atop the keyboard like Schoenberg's early piano pieces (but with a funky lilt) to Holcomb's witty double-jointed homage to stride piano, "Up Do," each track has its own shapely personality. Both Horvitz and Holcomb inlay these pieces with appealing, up-front tunes, but dig deeper and you'll hear canny, complex musical structures that reward repeated listening.

For a disc issued in fall 2004, this CD-release gig is long overdue. "The only touring we did for Solos was in Europe at the end of last year," recalls the perpetually busy Horvitz, who, along with wife Robin Holcomb, plans to share a solo set at the piano, in this case the Triple Door's Steinway nine-foot concert grand.

Additionally, odeonquartet performs a movement from Horvitz's string quartet Mountain Language along with other quartets by Thomas Oboe Lee ("Morango… almost a Tango"), Nathan Grigg (the recondite "init"), and Stuart Diamond ("Skies of Thunder Moon"). At the end of the night, odeonquartet joins Holcomb on piano and Horvitz on electronics for Whispers, Hymns, and a Murmur scored for string quartet and improviser. CHRISTOPHER DeLAURENTI

Catch Robin Holcomb and Wayne Horvitz Sun Apr 24 (The Triple Door, 216 Union St, 838-4333), 7:30 pm, $16.