The ZynAddSubFx synthesizer 3.0 release has many improvements and is worth to install. A procedure to build it is given at this URL : https://github.com/zynaddsubfx/zyn-fusi ... g-on-Linux but it requires some tweaking :
1) comment line 100 and 101 of the ruby script build-rpi3.rb because the file ZynAddSubFX_C_Owl_Alvarez_full_bank.zip isn't downloaded preliminary by the script
2) change "ruby build-linux.rb" by "ruby build-rpi3.rb"
3) the script produce a file named zyn-fusion-linux-3.0.3-patch1-rpi3-release.tar.bz2 where it puts the build results and that's this file to tar next.
At the end of the procedure you'll have 4 new entries in the main menu but it's better to create another that launch zynaddsubfx without any parameter.