Hi DOSBox devs. I recently released a DOS TSR that emulates an 'intelligent mode' MPU-401 interface (http://bjt42.github.io/softmpu). The high-level emulation uses mpu401.cpp/midi.cpp from DOSBox svn with a few modifications.

Thanks to Srecko, Qbix and any other DOSBox devs involved with this 😀

Haven't tried running it in DOSBox btw. It does work in MS-DOS running under Bochs.