Tap dancing is a unique form of dance because its actions are intended to
produce a variety of percussive sounds. Tap dancers frequently perform as
musicians in an ensemble; sometimes as vocalists or instrumentalists.
These percussive sounds are integral to the musical performance, and on
occasion the rationale for the song's composition.

Feet and hand movements are precisely timed in a fashion similar to drummers,
creating unique percussive sounds through intricate body movements. A dance
movement can produce multiple sounds. The method of percussion also creates
timbre, variability of impulse, attack, and decay. An example comparison would
be a drummer's "rim shot" and the Tap dancers' "Stomp".

Kahnotation was developed in the 1930s by Stanley Kahn and was published in
1951, making it the second oldest dance notation in continual use. Stanley
Kahn is considered a legend in the tap community, recognized as such by the
International Tap Association for having created Kahnotation and for having
taught tap dance for sixty years until his death in 1995. The notation has
been used in training and choreography for decades.