About Tenor Trombones:
A descendant from the 18th century (Baroque period) instrument known as the sackbut, the modern trombone has remained relatively unchanged in the past 100 years. The most popular trombone is often referred to as the tenor trombone, due to the approximation to the tenor range of the human voice. In fact, it’s often noted that the trombone is the wind instrument that most closely resembles the range of the human voice. And for that reason, the tenor trombone is often found in a number of different settings from solo performance to trombone ensembles, quartets and concert bands / wind ensembles.
There are many different types of tenor trombones as the music needs have evolved, and also as manufacturing capabilities have evolved among the major manufacturers. Trombones utilize a hand slide to change the overall length of the instrument, and resulting overtone series. In fact, the trombone is the only instrument that changes shape while you play it.
The most common way to differentiate different types of tenor trombones is by either the bore size (the tubing diameter measured in inches) or the use/type of f-attachment. Bore sizes will range for .484” (commonly used for jazz performance) to ..547” or .562” (commonly used in larger band or orchestral performance). The most common bore sizes are .500” which is found on most beginning or student instruments, and .547” which is found on most step-up or advancing/professional level instruments. The basic concept is that the larger the tubing (or bore size) the more air it will take to produce a sound, and the resulting sound will be broader and richer the larger the bore size. However – the additional effort needed for larger bore instruments is a trade-off to endurance. So ultimately the player has to find the instrument that is the right combination for their needs.
The f-attachment was developed as a way to extend the range of the trombone without changing the overall size/tubing length and key center. Additional tubing located in the bell section of the instrument lowers the pitch of a perfect 4th with the simple press of a trigger. The trigger will rotate a valve which redirects the airflow from the straight (normal) tubing to the additional tubing of the f-attachment. In addition to extending the usable low range of the trombone, the f-attachment tubing has the added benefit of some alternate combines for the 6th and 7th positions on the slide.