Instrumental idiom

For different styles of music, see Music genre.

Non-idiomatic trombone part  Play (help·info). Slide positions above the score indicate the large and swift change from the first to higher and then the highest positions required.

In music, an instrumental idiom refers to writing, parts, and performance, those being idiomatic or non-idiomatic depending on how well each is suited to the specific instrument intended, in terms of both ease of playing and quality of music.

For example, the trombone is played with a slide, making it one of the few wind instruments capable of glissando or sliding. However, pitches are different harmonics from the harmonic series on different slide positions. Thus, in the lower range, significant movement of the slide is required between positions, but for higher notes the player need only use the first four positions of the slide since the partials are closer together, allowing higher notes to be played in alternate positions. As an example, F4 (at the bottom of the treble clef) may be played in first, fourth or sixth position on a standard B♭ trombone.

There are cross-instrument guidelines. For example, it is difficult to begin playing very quietly in the upper or lower range of an instrument, (it taking more energy to produce sound) with tone quality and/or intonation often suffering. Use of extended techniques and writing in or beyond the highest or lowest range is not recommended, especially for student ensembles, unless writing for a specific performer.