Period performance is a sundry old can of worms.

Sometimes the use of historic (or replica) instruments is a straight means to an end - the end being special colour palettes that modern instruments gloss over. Other times it feels as though the instruments are the end in themselves.

The Chiaroscuro Quartet's concert on Monday was a superb example of the former; this programme headed by Australian clarinettist Nicola Boud veered more towards the latter.

Which wasn't necessarily a bad thing, if you happened to be especially curious about the kind of clarinet sound that Mozart or Brahms had in their heads. Boud used three different clarinets, starting on a sweet-sounding boxwood with five keys (modern descendants have 17 or more) and graduating to a raspy late-19th century replica.

It felt like an illustrated lecture without the lecture - a trot through the evolution of the clarinet and the correlated way that composers wrote for it. Pianist Kristian Bezuidenhout also switched about, from a delicate 1800-style fortepiano to a mellow 1850s Erard.

Early wind instruments are devilish beasts to play in tune, let alone prettily, and Boud's control was heroic. If the opening of Mozart's Kegelstatt sounded a tad mannered, the trio (with violist Sophie Gent) had found their swing by the gutsy finale. Soprano Sabine Devieilhe sang long, occasionally shrill lines in Schubert's Shepherd on the Rock; Jane Gower contributed a hearty buzz of a 19th century bassoon sound to Glinka's Trio pathétique. Boud ended with a beautifully lyrical account of Brahms's Eb Sonata, but Bezuidenhout's ornaments and rolled chords were cloying - he made the first movement's coda sound like a schmaltzy parlour song.