SpectMorph win, Linux, MacOS
Linux LV2 plugin – preferred for all sequencers that support LV2
VST plugin – especially for proprietary solutions that don’t support LV2
JACK standalone – application using JACK for midi input and audio output
Windows VST plugin – 64-bit VST usable in many Windows DAWs
macOS VST plugin – 64-bit VST for macOS 10.9 and later
SpectMorph is a free software project which allows to analyze samples of musical instruments, and to combine them (morphing). It can be used to construct hybrid sounds, for instance a sound between a trumpet and a flute; or smooth transitions, for instance a sound that starts as a trumpet and then gradually changes to a flute. In its current version, SpectMorph ships with many ready-to-use instruments which can be combined using morphing.
SpectMorph is implemented in C++ and licensed under the GNU LGPL version 3.