Many people have questioned the validity of the "Big Five" label frequently attached to a certain group of American orchestras (New York, Boston, Chicago, Philadelphia and Cleveland). Are they really the best five? Are there no others which match them?

Of course there are. An excellent case in point is the Pittsburgh Symphony Orchestra, which under its years with conductor Mariss Jansons as music director (1997-2004) and now with our very own Andrew Davis at the helm, has risen to be one of the most exciting ensembles on the US orchestral scene.

Tonight, Prommers will get a chance to hear for themselves when the Pittsburghians come to the Albert Hall. Unfortunately, Andrew Davis has had to pull out of the concert for health reasons but conductor Leonard Slatkin (pictured) is stepping in to fill the breach and the programme remains unchanged.

It starts with Ives's Symphony No.2, a visionary mix of Brahms, Dvor.·k and New England hymn tunes. The concert continues with the charismatic Chinese-American pianist Lang Lang playing Chopin's Piano Concerto No.1 and then, in an unusual break with tradition, the concert finishes with an overture: Strauss's Till Eulenspiegel.

Tonight, Royal Albert Hall, Kensington Gore SW7, 7.30pm, £5 to £40 (limited availability). Tel: 020 7589 8212. www.royalalberthall.com Tube: South Kensington/ Knightsbridge