You’ve got to breathe like a St Bernard dog . . . Now imagine you have a stomach as large as mine . . . Choose a note you like and hurt it.” The speaker was Simon Wills, London Philharmonic Orchestra trombonist, and he was giving this advice to a group of 15 or so young brass players at the Royal Festival Hall.

The gathering was part of Brass Blast, a weekend of music-making organised by the LPO. Harrison Birtwistle, the orchestra’s composer-in-residence, supplied the idea that was the focus of the weekend: the construction of a “Wall of Brass”, whose “bricks” would be music written by Birtwistle’s composition students across the Thames at King’s College, London.

The bricks were to be rehearsed over two days and then performed in the Queen Elizabeth Hall foyer on the Monday, as a prelude to an LPO concert featuring works by Birtwistle. In addition to work on the wall, the weekend saw master-classes featuring the trumpeter Hakan Hardenberger, conductor Elgar Howarth, and LPO principals; the rehearsal and performance of sections from Mussorgsky’s Pictures at an Exhibition, in which LPO members played alongside less experienced players; and a brass recital by Royal College of Music students.

The emphasis of the weekend was on “interaction rather than classes,” in the words of James Wilson, LPO education administrator. “Monday’s performance of the Wall of Brass was a focus, but the journey on the way to getting there was as important as the arrival. That’s the point of the weekend - the process of collaboration between a variety of instruments and performers.”

Interaction and collaboration was certainly in evidence right from the Brass Blast’s first morning. The instrumentalists - more than a hundred of them, aged 11 and upwards and mostly from the London area - were split into groups to be confronted for the first time with the “bricks” - much of whose music was in styles unfamiliar to them. (One instruction in the score was “Instruments . . . must avoid playing the same note as their neighbours.”) Each group was led by an LPO brass player - the charismatic Wills was perhaps the most popular - and had the benefit of a Royal College of Music student sitting in on workshop sessions, together with a composer. Bricks were tried out and in some cases modified as a result; Ross Lorraine, assistant professor of composition at King’s, oversaw revisions suggested by players, by fellow composers and by Birtwistle himself, who could be seen ambling from one group to another to offer advice. “We had to adapt as we went along,” said Lorraine, who worked late into the night on the final version of the Wall of Brass.

Kevin Nicholls, a peripatetic brass teacher with the Bedfordshire music service, who had brought some 30 youngsters down by coach for the occasion, thought “the music was a lot easier than I thought it might be.” It was, however, “the kind of music the students would never do normally.” His principal motive in encouraging his students to attend has been “so they can hear what a professional sounds like.”

“Inspiration for young players” was one of the main pluses of the weekend for Ros Asher, music adviser for the London Borough of Harrow, who had accompanied 33 “intermediate level” 11- to 17-year-olds to the South Bank. “These kinds of projects are critical for the future of living music,” she added. “The kids were listening to and watching professionals, and looking at composition from the inside.”

Although the weekend was free to participants, the LPO’s generosity seems not to have gone unrewarded. The concert that followed the 20-minute foyer performance was unusually well attended for one featuring two works by the “difficult” Birtwistle; obviously Brass Blast children - and their parents - had swollen the numbers.

As for the future, the LPO is already planning a similar weekend in the summer, for percussion instruments; woodwind and strings will come later. The next event will probably be a Bash rather than a Blast, but the title - or indeed the content - is not settled yet. “The same idea will apply, though, ” says James Wilson. “For a first event of its kind, the Brass Blast went surprisingly well. It was a fantastic mingling of all ages and abilities. ”

Ros Asher echoes this, citing a remark by a young trombonist who had sat beside Simon Wills for the performance of Pictures at an Exhibition. “He said ‘I can’t play all the notes, but it was a thrill to sit next to someone who can’.”

LPO Education Department: 071 833 2744.