Jonathan Biss BEETHOVEN/SCHUMANN PIANO WORKS (EMI)

First albums by young virtuosos are often just exercises in virtuosity. But 23-year-old Jonathan Biss is not only a student of Leon Fleisher, he’s also the son and grandson of distinguished musicians. And his first album includes two of the most profound piano works ever written: Beethoven’s Appassionata Sonata and Schumann’s Davidsbündlertänze ("Dances of the League of David," Schumann’s imaginary club of artists who fight the Philistines).

Earlier this month, Biss stepped in for the ailing Andreas Haefliger two days before a scheduled BSO concert and played Beethoven’s Emperor Concerto under James Conlon. At the Thursday performance, he missed a couple of crucial notes, his timing seemed a little off (he rushed the first movement), and his tone had a steely edge. He’d have had to be some rara avis not to have been nervous. When I listened Friday on the radio, the performance sounded more settled. Biss seems to understand how the Emperor is put together, and he focused his energy, especially in the brief but searching slow movement. I hope he outgrows the dramatic arm flinging and leg stomping and the sideways, heavenward head tilt whenever the music turns æthereal. He’s too good to need to try to look like the music he’s playing.

Biss has the chops for Schumann’s loudest and fastest passages — the ones that sound like Hungarian drinking songs and patriotic anthems — and the delicacy for the most interior passages. He’s especially touching in the very last dance, where Schumann exchanges his previous nostalgic longing for a return to the real world, a moment too many other pianists trivialize. Biss still lacks the kind of flexibility within phrases that makes the music feel completely lived (repeats seem merely repeated), and he rushes a little (he could learn a lot from watching Balanchine’s great ballet to this music). He has more consistent success with the more overt drama of the Appassionata and Beethoven’s quirky, rarely performed G-minor Fantasy. This debut may promise more than it delivers, but it’s far more than just a promising start.