Abstract: Trumpet with linear or rotary pistons, such as B-flat, C, D or E-flat trumpets, wherein the bottom of the tuning bow comprises a conical widening and the lower tube of the tuning slide assembly slides outside the tube integral with the set of pistons, which integral tube is shortened with respect to the upstream end of the lower tube of the slide assembly in the abutting position, the remaining part of the bore being substantially cylindrical and of same diameter. When dividing the tuning bow into six sections of equal axial length, the conical widening starts in the fifth section and the upstream end of the tube integral with the set of pistons is situated just beyond a seventh section having the same axial length as the others.