Types of Trombone - in Order of Pitch - Tenor Trombone - F Attachment

F Attachment

Many modern tenor trombones include an extra attachment of tubing - about 3 ft or 1m in length - which lowers the fundamental pitch from B♭ to F. There are two different forms of this tubing, open wrap and traditional, or closed, wrap. The traditional wrap is curved and fits inside the main tuning slide while the open wrap extends past the main tuning slide and only has one curve in it. The F attachment is engaged by using a trigger which operates a valve (this is different from the three-valved valve trombone). This type of trombone is typically built with a larger bore size (0.525" or 0.547") and is known as a B♭/F trombone, F-attachment trombone, or trigger trombone. Trombones without this feature have become known as straight trombones.

The F attachment originated in an instrument developed by German instrument maker Christian Friedrich Sattler during the late 1830s and patented in 1839. It gained popularity at a time when the older German E♭ and F bass trombones had fallen out of favour with orchestral players and were being replaced by a B♭ tenor trombone with a wide bore and large bell proportions. This instrument was known as the tenorbass trombone (German Tenorbaßposaune)—it was a tenor trombone in B♭ with the bore and bell dimensions of a bass trombone, and was used to play both tenor and bass trombone parts.

Sattler used the rotary valve attachment to provide a way to play the notes between the fundamental B♭1 (first position) and the second partial E2 (seventh position). The valve allowed players to produce low E♭, D, D♭, C (and, with adjustments, B), thus making the full range of the old bass trombone in 12' F available and extending the chromatic range of the tenor trombone through the fundamentals to E1.

Sattler's intention was not to create a trombone that would replace the older F and E♭ bass trombones, but rather to provide an instrument with the ability to cover the range of the bass and tenor trombones seamlessly. The tenorbass trombone did replace the older bass trombones, however, and the bore and bell size were increased later in the nineteenth century to allow for models designed specifically to cope with bass trombone parts; modern bass trombones are derivatives of these late nineteenth century B♭/F trombones that are used to play parts originally intended for the bass trombone in G, F or E♭. Since engaging the valve changes the tubing length, additional alternate positions for notes become available. The resulting increase in facility and the addition of the low E♭, D, D♭ and C make these instruments popular among experienced orchestral tenor trombonists.

As the tubing length increases by a factor of one third, the distance between each position must be one third longer when the valve attachment is engaged. This results in only six positions being available, as the slide is too short for what is effectively a bass trombone in 12' F. Because of this, the B two ledger lines below the bass staff is impossible to play unless the attachment is tuned down to E, or the embouchure is loosened. The range of the tenorbass trombone is therefore E1 to B♭1, then C2 to D5.