Trombone + brass instruments
Good tonal blend with the other brass instruments.
Trombone + trombone
In unison and in octaves: metallic sound, impression of power.
Trombone + trumpet
Good sound combination, makes the trombone sound brighter. Particularly good blend in the lower register.
Trombone + French horn
Overall sound rich and mellow, intensified by the trombones in ff passages. In higher registers the trombone makes the horns sound brighter, the rest of the time the metallic trombone sound is masked by the horns. 1 trombone = 2 horns when the written dynamic levels correspond.
Trombone + tuba
Although it has a different timbre, the tuba is often used as bass to the trombone section. The main reason for this is to produce a full-sounding foundation in tutti passages. The trombone sounds much more compact and focused. The tuba can either be used on its own as bass to the trombones (as a fourth trombone), in octaves, or in unison with the bass trombone. These last combinations are often recommended. The overall effect is one of expansiveness and mellowness. The brightness of the trumpets and trombones is subdued.
Trombone + woodwinds
The combination of trombones and woodwinds produces a very patchy blend, so homogenous effects cannot really be achieved.
Trombone + oboe
are heard distinctly as a rule, although blending is good when the trombone is played with a mute.
Trombone + bassoon
The bassoon masks the metallic quality of the trombone’s tone, which results in delicate contours in the middle and lower registers and in piano passages. For the reinforcement of sound in tutti passages the octave combination of trombone and low woodwinds serves as the bass.
Trombone + strings
The combination with strings does not generally produce homogeneity. Trombones play in unison or in octaves with the cellos and double-basses, fleshing out the sound and playing a supporting role. The result is a concentration of the sound. If a trombone bass part is also carried by a double-bass the sound is projected more effectively.