This paper addresses the description and the interpretation of differences concerning the sound of different trumpets, i.e. the sound identity of instruments. Three different trumpets, obtained by geometrical variations of the leadpipe, are considered. After a measurement of the input impedance of the trumpets, they are first simulated using the harmonic balance technique, and second played by a “real” musician. Different playing conditions are considered, either for the simulation (virtual musician defined by the control parameters of the simulation) or for the “real” musician (playing at different dynamics). The two populations of sounds produced are characterized by their spectrum in permanent regime. The differences between the instruments, played or simulated, are next described by data analysis techniques (boxplot, principal component analysis, discriminant analysis). The objective is to discriminate the variability in the sounds due to the musician (virtual or real) to those due to the instrument itself. Results show that a sound identity of the instrument can be defined, in particular for crescendo sounds. Even if the simulated sounds and the sounds played by a musician are obviously very different, similarities in the differences between real and virtual sounds can also be noticed.