![trombone trigger](https://i0.wp.com/playingbrass.com/wp-content/uploads/2020/04/image-34.png?resize=578%2C187&ssl=1)
Single trombone trigger
Some trombones have a trigger or “F” attachment. When you press the trombone trigger, it makes the instrument longer by 5 semitones (equivalent to 6th position). The instrument will produce a low F in the 1st position instead of a Bb when you press the trigger (or valve). Therefore the trigger is often referred to as an “F attachment”.
The trombone trigger is equivalent to a 4th valve on a valed instrument |
The trigger provides further options when playing notes in 6th or 7th position. The trigger make the trombone much longer when used in combination with the slide by adding another 6 positions in length to the 7 positions on the slide. The player uses the trigger to continue playing all the way down to a low C (just above pedal Bb) from a low E in 7th position. With only 1 trigger, the instrument still can’t be made long enough to reach a low B natural.
![](https://i0.wp.com/playingbrass.com/wp-content/uploads/2020/04/image-32.png?resize=30%2C39&ssl=1)
Double trombone trigger
![double trigger](https://i0.wp.com/playingbrass.com/wp-content/uploads/2020/04/image-36.png?resize=282%2C169&ssl=1)
The 2nd trombone trigger on some bass trombones opens several more semitones of tubing. By combining two triggers with the slide, the trombone can be made much longer than usual; allowing it to play much lower notes, including the low B natural.
Length of positions
When you press a trombone trigger, you are lengthening the whole instrument. The length of the instrument determines how long each position should be to reach the next semi-tone. When you press a trigger, you make the slide positions become so long, that the slide is only long enough to cater for 6 positions, instead of the usual 7 positions.
To find the new longer positions when the trigger is pressed, do the following;
- Play F in 1st position, press the trigger and tune the trigger to sound the same.
- Play E in 2nd position, press the trigger and find the same note using a long 2nd position. Use the trigger and this long 2nd position to play the E an octave lower.
- Play Eb in 3rd, then find the longer 3rd by pressing the trigger, and so on until you get to C.
Find the (even longer) positions using a double trigger using the same method.
Why does the slide only have 6 positions when the trombone trigger is pressed? To lower a note by 1 semitone, the overall length of the trombone needs to increase by 6%. As the instrument becomes longer, the additional tubing needed to produce 6% becomes longer. When the first 6 positions are played using a trigger, each slide position need to be further apart than usual to change the pitch by a semitone. The slide is then only long enough to accommodate 6 positions. |