In a method for generating an identifier for an audio signal including a
tone generated by an instrument, a discrete amplitude-time representation
of the audio signal is generated at first, wherein the amplitude-time
representation, for a plurality of subsequent points in time, comprises a
plurality of subsequent amplitude values, wherein a point in time is
associated to each amplitude value. Subsequently, an identifier for the
audio signal is extracted from the amplitude-time representation. An
instrument database is formed from several identifiers for several audio
signals including tones of several instruments. By means of a test
identifier for an audio signal having been produced by an unknown
instrument, the type of the test instrument is determined using the
instrument database. A precise instrument identification can be obtained
by using the amplitude-time representation of a tone produced by an
instrument for identifying a musical instrument.