Trombone Glissando Checker

The glissando is one of the trombone's most distinctive capabilities — a smooth, continuous slide between two pitches that no other brass instrument can produce in quite the same way. But it comes with a catch: not every pair of notes will work. Whether a glissando is possible depends entirely on the physics of how the trombone produces sound, and figuring it out from first principles is time-consuming for composers and arrangers who don't play the instrument.

This tool takes the guesswork out of it. Select a start note and an end note, hit Check Glissando, and you'll get an immediate answer along with a technical explanation of why.

How to use the tool

1. Select the start note — click a key on the keyboard or drag up and down on the left staff. The blue staff shows your current start note.
2. Select the end note — click the right staff or a keyboard key to set the destination. The amber staff shows the end note.
3. Switch between Bass Clef and Tenor Clef if needed (both staves update together).
4. Press Check Glissando to see the result.

The result banner will be one of three colors:

• Green — Yes, Possible. The two notes sit on the same partial of the harmonic series, so the slide moves in one unbroken direction between them.
• Amber — Maybe. The glissando is theoretically available but comes with a significant caveat (see below).
• Red — Not Possible. The notes live on different partials. To connect them, the player would have to switch to a different partial mid-move, which breaks the continuous sound.

Why glissandos work the way they do

The trombone produces pitched sound by vibrating the player's lips inside the mouthpiece. Like any brass instrument, it can only sustain notes that belong to the harmonic series — a fixed sequence of pitches built on a fundamental. On the trombone, each harmonic is called a partial, numbered upward from the lowest: pedal tones (1st partial), then the 2nd through 9th partials in normal playing range.

The slide has seven positions. Moving the slide outward lowers the pitch in small steps; each position gives you one note per partial. A glissando is possible only when both notes belong to the same partial — because the player keeps the same lip tension and air stream throughout, letting the slide do all the work. If the notes are on different partials, the player would have to switch embouchures mid-move, which produces a break rather than a gliss.

For a deeper look at how positions map to notes, see the trombone slide chart and alternate positions on trombone.

Partials for tenor trombone

Partials for tenor trombone with f-attachment

When using the f-attachment there are only 6 positions available.

The "Maybe" categories explained

Maybe — Very Difficult

Some notes are technically on the right partial but are simply hard to hit cleanly as a starting pitch — certain positions on the higher partials are notoriously unreliable for a clean attack, even for experienced players. The 7th partial in 1st position (A♭) is a special case: the note is very flat in pitch on this partial, so players and composers need to be aware of the intonation. The tool flags these situations rather than silently marking them green.

Maybe — Advanced (Pedal Tones)

Pedal tones are the 1st partial — a register an octave below the normal low range. They require a very relaxed embouchure and a specific low-pressure air stream that most players develop only with experience. Glissandos using pedal tones are found in professional orchestral and jazz writing but should be used with care in other contexts.

Maybe — Requires F-Valve

Trombones fitted with an F-attachment (a rotary or axial valve that adds a length of tubing in F) gain access to additional partials that bridge gaps in the low register. Some glissandos are only available via these F-valve partials. This result means the gliss works, but only on an instrument with an F-attachment — not on a basic straight tenor trombone.

Who has an F-attachment? In an orchestral setting you can safely assume all trombone players have one — it is standard equipment in classical playing. In a jazz big band the picture is more varied: the 1st and 2nd chair tenor trombonists often play straight horns without a valve, the 3rd chair typically has an F-attachment, and the bass trombone seat uses a two-valve instrument. If you are writing a glissando that requires the F-valve for a big band tenor part, check which chair it is for.

Bass trombone: more options, more complexity

Most modern bass trombones have two valves. The first is in F, the same as the F-attachment found on many tenor trombones. The second valve is typically tuned to G♭ or G (though other tunings exist), and with an independent valve system — where each valve can be engaged separately or together — it opens up a range of additional harmonic series not available on the open horn or with the F-valve alone.

This means bass trombone players have access to glissandos that are simply out of reach on tenor trombone, particularly in the low register. However, because players and orchestras use different second-valve tunings, a glissando that works in G♭ may not be available in G and vice versa. Unless you are writing for a specific player and know their setup, it is safest to treat the two systems separately and write only to the options available with either tuning — or to consult the player directly.

For more on the different configurations available, see what are the different types of trombones.

Tips for composers and arrangers

• Glissandos across a wide interval are often more effective than narrow ones. A half step on the same partial usually just sounds like a smear; a fifth or more makes the effect unmistakable.
• Give the player enough time to get there. A gliss spanning the full range of the slide takes time to execute cleanly. At fast tempos this becomes rushed.
• The direction of the line matters. Downward glissandos (extending the slide) tend to have a falling, relaxed quality. Upward glissandos (retracting) feel more urgent.
• Check the starting note carefully. The tool will warn you if the starting pitch is in a difficult position — this is worth heeding. A beautifully written gliss that begins on an awkward attack note may not land in performance.
• If the tool says No, the player will still try. Trombone players encounter impossible glissandos regularly and know how to fake them — approximating the effect with a partial slide move, a lip gliss, or a combination of both. It won't be the clean continuous sweep of a true gliss, but it won't be silence either. If the effect matters more than the precision, it may still be worth writing.
• Tenor clef is common in the upper register. Use the clef toggle in the tool to check notes as they would appear in a real part. For more on trombone clef conventions, see trombone keys and clefs.

If you are new to writing for trombone, how to play the trombone gives useful background on the instrument's mechanics and range.