What on earth are we to make of Richard Strauss's Violin Sonata?
This almighty torrent of purple, from a 23-year old master of everything but his own voice, is probably best approached as a kind of adolescent concerto.
That was certainly how Tasmin Little and Piers Lane tackled it. Little's magnificent, fluid stream of tone - sonorous in the bottom register, opening to a gleaming blaze of sound on the E string - and Lane's poetic, rich-hued and endlessly responsive piano, wrung everything possible from this near-miss masterpiece.
But virtuosity and panache are basic requirements for the Strauss. What made Little and Lane's account so deeply enjoyable was the imagination with which they illuminated its dustier corners.
Little's veiled response to Lane's gentle arabesques in the Sonata's central Improvisation made Strauss's tinsel seem, for a moment, like genuine gold.
The same approach had earlier made a persuasive case for a true rarity - Paul Hindmarsh's reconstruction of Frank Bridge's unfinished 1904 Violin Sonata.
While the melodic inspiration in this early fragment may not be vintage Bridge, the work's freshness, confidence and haunting tenderness all reaffirmed a long-held conviction - everything by this composer is worth hearing. Little and Lane's performance served it nobly.
Bach's Sonata BWV 1019 fared less well - perhaps because even the most expressive performance can no longer make Bach ring true in a 2000-seat hall. The tender confidences that open Brahms's A major Sonata suffered from the same lack of intimacy.
In every note, both performers created a quality that's too easily undervalued - beauty.