An F trombone is a type of trombone that was popular during the Romantic period but is now obsolete and rarely used. Although some trombone players own custom versions, it is no longer manufactured for the mass music-playing market. The old style F trombone was usually a bass trombone. These are essentially historical, obsolete instruments that can be played but are rarely used in orchestra arrangements, and they are usually only used in performance if one of the performers owns one. F triggers are attachments on some modern trombones that effectively lengthen the body of the trombone, allowing it to temporarily convert into a F trombone.
Modern bass trombones differ from F trombones in that they have wider pipes, are tuned to B flat, and have triggers that allow the instrument to be tuned to F or D to play lower notes. Bass F trombones are also known as European-style bass trombones, and they are available in G as well as F. Bass trombones are generally larger and play lower pitches than B flat tenor trombones, which are the trombones most people are familiar with. A B flat/F trombone is a tenor trombone that can be converted to a F trombone with the use of a trigger.
When an instrument is said to have a pitch, such as F, G, or B flat, it means that when the instrumentalist plays a written C, the instrument sounds at that note. This is done in order to center the instrument’s notes on the most readable part of the staff, avoiding the use of too many ledger lines. When a composer wants to use notes that aren’t on the main staff, she can draw short, dash-like lines above or below it to serve as the staff for higher or lower notes. Using many ledger lines can make the music more difficult to read because an instrumentalist usually plays notes centered on the main staff.
The fundamental pitch of an instrument, which is the note that plays when the instrument is in its home position with no keys pressed, is often indicated the given pitch of the instrument. When the outer slide on a trombone is fully closed, this is the note that plays. When a F trombone is played with the slide closed, it sounds like an F, and a F trombone player may have transposed music that shows a notated C for a sounded F.