SlackBuildsOrg/audio/rubberband

rubberband (audio time-stretching and pitch-shifting)

Rubber Band is a library and utility program that permits you to
change the tempo and pitch of an audio recording independently of one
another.

Rubberband can be built with optional Java JNI support. To do this,
install one (and only one) of the zulu-openjdk8, jdk or openjdk8
packages, make sure its profile script has been sourced (normally
by logging out & back in), and build rubberband with JAVA=yes
set in the environment. Currently, this has only been tested
with openjdk8.