The Scottish Proms was once considered a major summer concert series, before it started along the route of increasing commercialism and waning artistic merit. The RSNO's current management, however, has given the concerts something of a revamp. If the current series (no longer called Proms) is still aimed at the populist end of the market then at least it offers the sweetener of a trio of concerts featuring the combination of Stephen Hough and Rachmaninov.

Few pianists can play Rachmaninov like Hough. Having already dispensed with the Second Concerto and the Paganini Rhapsody in the first of his debut appearances with the RSNO, in the last concert he turned his attention to the Fourth Concerto. Less popular, less self-indulgent than the rest, it is in many ways a more convincing whole, especially in Hough's hands.

His performance combined bravura brilliance with nimble-fingered delicacy, and was powerful but never forced, expressive without being sentimental. The orchestra, under Costa Rican conductor Giancarlo Guerrero, never had a hope of keeping up with the breakneck pace and mercurial agility with which Hough took the finale, but it made for an exhilarating ride.

Elsewhere, the concert stuck firmly to populist ground with an American theme as Gershwin's Porgy and Bess suite followed hard on the heels of Copland's Billy the Kid. The result was two unexceptional performances in rather too close proximity of two colourful, pictorial works. The turnout in the Royal Concert Hall was decidedly sparse; not even the resounding ovation given to Hough could disguise that this is a rather tired format desperately in need of an overhaul. Just as well that RSNO chief executive Simon Woods promises radical changes for next year.