When clarinet sounds bad – Identification study Abstract In wind instruments, tone quality is an important sound feature which strongly depends on the player. The subject of this study was to examine perceptually when a clarinet tone sounds bad, how it sounds, and what this depends on. Analysis of clarinet recordings, interviews, and a listening test gave insights into the most common mistakes and their causes. The results show that professional clarinetists and teachers can identify the possible cause of a bad tone quite reliably. Also, a number of common methods for avoiding typical playing errors were acquired. Spectrum characteristics of bad clarinet tones were analyzed. It was not always feasible to find common characteristics for a certain error category, but some tendencies and cues that distinguish between categories of bad tones have been found and are discussed. Algorithmic descriptions for differentiation of bad tones were compiled with the purpose of finding bad tones in a recording automatically. This is an important issue in computer-aided learning, especially for beginners.