Chris Stearn, principal bass trombonist at Scottish Opera, and Professor at the Royal Scottish Academy of Music and Drama was recently invited by Roger Argente, principal bass trombonist in the Royal Philharmonic Orchestra and Head of Brass at Trinity College of Music to present a masterclass on the contrabass trombone. Adrian Cleverley, a Trinity trombone student wrote the following report of Chris Stearn's presentation.

Students from Trinity College of Music, London gathered in the Philip Jones brass room on 13 October to take part in a masterclass, which must be said to be a bit of a rarity, for this was on one of the most neglected instruments in the brass family - the contrabass trombone. Roger Argente, professor of all things low and farty at TCM, recently bought a contrabass trombone through the college and it only made sense that he got someone in to show us how to blow the thing.

He contacted Chris Stearn, bass and contrabass trombonist of the Scottish Opera and professor at the Royal Scottish Academy of Music & Drama, who, funnily enough, also helped design this monster of an instrument. Chris Stearn is probably the most knowledgeable person on the contrabass trombone you'll ever have the pleasure to meet, but if you look at his credentials they explain themselves really. Born in 1955, he started learning the trombone at an early age and soon began studies at the Guildhall School of Music & Drama under Denis Wick and Peter Gane. After a few years' freelancing he joined Scottish Opera in 1984 and has been there ever since. "That's a lot of Ring cycles in that time!"

Designs for the new contrabass trombone began about six years ago to build an instrument with the classic rich sound of the trombone but without the complications of an instrument with too much plumbing - a problem that most manufacturers and bass trombonists find too often these days. The contrabass trombone has been around since the seventeenth century and was of such proportions that it was seldom used. Hard to build, heavy and foggy in tone, it was very unstable to play. However, it was natural that Wagner wanted to use this instrument to extend the brass sonorities for his Ring cycle.

Chris Stearn and Michael Rath began work and after a few years' experimentation the Rath R90 contrabass trombone was unveiled. This is the first contrabass trombone to be built in Britain since the 1930s when Boosey & Hawkes made the B flat instrument known as "King Kong". Priced at £6,495, it is the first F contra to be made outside of Germany. It has a five position slide with René Hagmann in-line valves and extension slides for the valves allowing them to be in E flat or D and C, flat C or B flat. The slide is 0.578" bore with a 10" bell, all in gold brass and comes with the new Rath CB1 contra mouthpiece.

The masterclass started with Chris performing one of his own compositions, McRories Glory, a piece for bass trombone and percussion. Chris said that this gave us the chance to hear the different sonorities of these instruments and also that it was easier to go down to the contra than go up to the bass.

Chris then moved onto his own custom designed Rath contra. Choosing music he said The Blue Bells of Scotland was out of the question, so chose Lament from Variations by Sally Beamish. This slow, expressive piece showed the melodious side of the instrument, but as pointed out by Chris, the sound was like that of a euphonium but with the attack of a trombone. Chris then performed a section (because the piece is 25 minutes in length) from the Sonata for Contrabass Trombone, a contemporary piece by trombonist John Kenny, involving experimental techniques and advanced music-making including blowing through the bottom of the mouthpiece, accelerating mimicking the sound of a train.

While performing, Chris compared the set-up of the two contras. Trinity's contra involves more valve movement, which has its benefits but difficulties in tuning, whereas Chris' instrument like (Richard Tyack's of the Royal Opera House) prefers to use the slide, giving a much more fluid feel and warmer sound.

It was not too long before there was some group participation and Trinity students Chris Aggett and Adam Smith played some excerpts from Das Rheingold, with Chris Stearn giving copious amounts of helpful advice. Both students played well on a relatively new instrument. Obvious problems occurred as the instrument is pitched in F and with the different valve set-ups, but also with the blowing technique. It is completely different from the bass trombone; air must be pushed down the instrument slowly as there is more resistance against the mouthpiece which can make production of notes in some registers very difficult.

One more issue pointed out to us by Chris was that virtually all of the fourth trombone parts in Das Rheingold are written for the contrabass trombone except for six bars and if the part calls for the bass trombone, it should be played on the bass. This brings up some difficulties in a performance, namely swapping between instruments. The important thing to remember is changing the blowing style into the bass trombone and remembering that you are now playing a differently pitched instrument. When asked how Chris prepares for a performance of the Ring cycle, he simply says that he doesn't. If he concentrates too much on playing either instrument, he is more likely to confuse himself when swapping. The best way he finds is to go in at the deep end - using the scare tactic to make himself concentrate.

The masterclass rounded up with a brief Q&A (I say brief but Chris could spend days talking about the contrabass trombone - he loves it so much). This was a very rare and exciting opportunity to see a real musician play such an extraordinary instrument. As a bass trombonist at Trinity, I am always keen to explore the depths of the instrument, thinking there would be a limit to how low you could go. A new door has now been opened to my musical world and it looks like the only way is down.