The trumpet’s sound is metallic, bright (but also dark in the lower register), intense, brilliant, powerful and stately. It projects best between G3 and G5.
If we draw a direct comparison between the C and Bb trumpets, which are the two most commonly used today, the C trumpet sounds brighter, more reserved and more sober while the Bb has a softer and more rounded sound.
Differences in the registers are relatively hard to locate and depend on the individual instrument and the mouthpiece used. Transitions between individual registers are smooth and tone color variations between them are not great.
F#3 – F#4
Metallic, dark, substantial, heroic. Not as rich in overtones as the upper register.
Played forte, notes in this register are sonorous and rounded.
In its low register the trumpet is well-suited as a metallic, dark, precise and agile middle voice in the orchestra and as such offers an effective contrast to the soft horns in the same register.
The lowest notes down to C4 are prominent, assertive, dark (though not weighty as on the trombone), eerie and portentous. These effects are often used for battle scenes in dramatic works.
G4 – F#5
It is here that the instrument’s sound comes into its own: brilliant, full, rounded, magnificent. A metallic brilliance that pervades the entire orchestra and cannot be achieved by any other instrument.
The ease of its playability makes it ideally suited for thematic tasks and solos, even when played piano, which is still clearly audible even in tutti passages.
G5 – C6
Bright, shrill, penetrating, vivid.
Up to C6: A homogeneous continuation of the middle register, although no longer so prominent.
The notes above this sound piercing and develop a particular quality appreciated especially by jazz musicians.