Considering the apparent simplicity of the development of the trombone, from the earliest recorded Renaissance instruments to the instruments of today, performing on the different trombones can be very problematic. Essentially we can divide the history of the trombone into four main periods: the Renaissance and Baroque, the Classical, the Romantic and, more recently, the Modern era.

Originally the trombone was a small-bore instrument, which generally featured a small bell flare. This was beaten and had thinner walls than the contemporary trombone. Three main types of trombone were used during the Renaissance period: alto, tenor and bass. These instruments were alternatively known as sagbuts, shagbolts, or sacqueboutes ("push-pull" for the non-French experts). They were played predominantly in small chamber groups and bands with strings, shawms, voices and cornetts. The typical repertoire played was Canzonas by the Gabrielis and Vespers by Monteverdi.

In my experience of performing such repertoire on both modern trombones and Renaissance copies, I have found many more advantages in playing on the so-called correct or original instruments. The smaller set-up lends itself to a better blend of sound with both the voices and other instruments, such as the cornetts and strings. The sound is smaller, more flexible and compact, and is more focused in the lower dynamics. It also gives the faster, more virtuoso passages more clarity. These instruments can be extremely brash, bright and edgy - a great match for the shawms and natural trumpets! These qualities lend themselves better to the acoustics of cathedrals and churches, but can sound extremely thin and breathy in some of the modern, Queen Elizabeth Hall types of concert hall.

After much experimentation with copies of these instruments, I have settled with Egger tenor and alto sackbuts, which are copies of original sackbuts made in Nuremberg. They are hand-made in Switzerland, at vast expense. They are not exact replicas as a few improvements and alterations have been made. The slide is chromed and has stockings, which works better than the brass slides of the originals. The Egger has standard round stays, whereas many of the early trombones had flat stays which made them extremely uncomfortable to hold. The beautiful and elaborate decoration on some examples made the instruments cumbersome due to the extra weight.

I have discovered that modern mouthpieces are not particularly suited to these instruments. They make the instrument too flat in the upper registers, especially on the alto, and they are rather dull and inflexible in tone colour. It is worth persevering with the Baroque mouthpiece. Its shallower cup and sharper throat enable one to produce the tone colours required. The Baroque mouthpiece has a flat rim with a sharp edge. It varies in diameter, as do many of the modern mouthpieces. I am not convinced that this is so important for producing the articulations required. The sharp edge can affect stamina in the more strenuous concerts.

The originals, and copies, do not have tuning slides or water keys - standard features on modern trombones. I was persuaded to have these added within my first week of purchase when the wonderful, solemn atmosphere of a concert was punctuated with gargling noises. I have not noted an alteration of sound, although the neurotic specialist may beg to differ.

As for tuning, the players of the Renaissance period added crooks. These were placed between the slide and bell sections, enabling them to adapt to the different organ and choir pitches of the day. Affluent players overcame this problem by owning several sackbuts in different keys.

The question of pitch is one of our biggest headaches in performing authentically today. It has been discovered through researching and scanning the literature, and from examining the pitches of original woodwind and stringed instruments, that we are required to play our sackbuts in pitches A=392, 415, 430 and 435. Sometimes, when the sun is shining, we do get to play our own standard A=440! Therefore we have had extra tubes made, and we adjust the altered harmonics by tuning with the slide. Another way to overcome the changes in pitch is, of course, to transpose, and this is the most recent concept in performing music from Venice, which is now required at A=465. It can really confuse the ear for pitching notes, especially when required to play in two different pitches on the same day. Very interesting rehearsals!

Some Renaissance groups insist on mean-tone temperament. If you think changing the trombone into different pitches is daunting, try this! For further, extremely complicated information, read from page 28 of Brass Instruments: Their History and Development by Anthony Baines. Have the calculator ready. Excellent results can be achieved if the ensemble uses this tuning system exclusively, but I have only experienced it with a few groups on the Continent. It is difficult to achieve the same effect in Britain as players tend not to specialise in one type of Renaissance trombone.

Performing music on authentic or original instruments does not end with the Renaissance period. It has progressed through the Classical and, more recently, the Romantic periods. Few Classical instruments have survived to the present day, to be available for viewing in museums. One such collection, the Bate Collection in Oxford, owns fine examples of instruments of this period. The Classical instruments that have survived are remarkably similar to those of the Baroque/Renaissance era. Some, however, have an extra garland and small bell flare.

France, at the time of Berlioz, developed a larger trombone with a wider bell flare. It is similar in size to the old brass band "peashooter" trombone. I have my own collection of "peashooters" that I use for most of the music of this period. I never thought the day would come when I returned to playing the kind of instrument on which I had my first trombone lessons - and I'm not that old!

There is a number of problems encountered with these instruments once one with a decent slide has been found. Silver plated slides tend to be heavy. They are extremely "woolly" in the range from middle F to the dreaded bottom B natural, which hardly exists at all. (The player should be wary of getting too excited as there are no springs at the top of the slide and one can easily knock a few teeth out.) This same feature, however, makes it easy to make a sound that blends well. In addition, this produces a more compact sound which blends better through the louder dynamics, but does not totally swamp the rest of the orchestra. Also, the quieter dynamics do not appear to lose their clarity of sound.

Recently, the London Classical Players have recorded some of the German Romantic repertoire on original instruments. We had the great pleasure of playing on a matching set of Kruspe trombones: alto in E flat, tenor in B flat and bass in B flat and F. The alto unfortunately had no tuning slide, which made the tuning rather difficult, especially as we were playing at A=435. Despite this disadvantage, it was the best trombone I have ever played. It had a medium sized bell and quite a small bore. The tenor was also small bore, but had a huge bell similar to the size of the bass. The bell is equivalent to the bell of the modern bass trombone. The bass also had a large bell with a relatively small bore. It had a novel press-button water key which kept its player very amused. They all produced a warm but more mournful sound, whilst retaining clarity in the lower dynamics.

I enjoy performing on these instruments despite the problems. The time spent tuning can be frustrating, but this is far outweighed by the tone colour and blend that can be produced to a better quality than on some modern instruments. There is certainly a place in the modern orchestra for such instruments, especially for the German repertoire.