What limits did the valveless Baroque trumpet place on performers?

The valveless Baroque trumpet, often referred to as a natural trumpet, placed significant limitations on performers due to its inability to produce a full chromatic scale. Because the instrument lacked valves or keys to alter the length of the tubing, players were restricted to the notes available within the natural harmonic series.123

These limitations included:

• Restricted Range: The instrument could only play notes belonging to its specific harmonic series, making it impossible to play a complete chromatic scale without mechanical assistance.312
• Dependence on Skill: Performers relied heavily on advanced lip control and embouchure to produce and tune notes, similar to the technique required for a modern bugle.12
• Intonation Issues: Certain harmonics, such as the 7th, 11th, 13th, and 14th, were inherently out of tune with the standard musical scale, requiring the player to use significant skill to adjust the pitch.2
• Register Constraints: To play melodies, trills, and ornaments, trumpeters were forced to play in the high, or clarino, register, where the natural harmonics are closer together and form a diatonic scale.42