Black MIDI Wiki

OmniMIDI, previously known as Keppy's MIDI Driver and Keppy's Synthesizer, is a MIDI synthesizer made by the BMT member KaleidonKep99.

It was first released on May 17, 2015 as a modified version of the BASSMIDI Driver. The user had to install the normal, unmodified version of the BASSMIDI first, then replace the required DLLs with the modified ones.

Its first self-contained release (Not relying on BASSMIDI Driver anymore) was version 1.5 bugfix 49, released on July 13, 2015.

Currently the de facto synth in the Black MIDI Team (With exceptions), it's able to achieve close to 1ms audio latency, without having to trade for audio quality.

It runs on the same BASS libraries as its sister-like synths, CoolSoft VirtualMIDISynth/CoolSoft VirtualMIDISynth 2 and BASSMIDI Driver, but unlike them, it also supports ARM64 releases of Windows.

Keppy's Direct MIDI API (KDMAPI)[]

Keppy's Direct MIDI API is a programming interface first introduced in release, and made available to developers with release

It allow developers to bypass the Windows Multimedia API, which is the cause of poor performance in legit runs of big and resource-intensive Black MIDIs.



  • It's a hybrid between the audio quality from BASSMIDI Driver (no stuttering) and the fluidity from CoolSoft VirtualMIDISynth 2.
  • There's no click noise when a note is killed.
  • Only one MIDI port, while the user is able to switch between soundfont lists. (Up to 16 lists - 8 are disabled by default)
  • Debug mode available, like CoolSoft VirtualMIDISynth 2.
  • Currently the only synth that works perfectly with Windows 8.x and newer.
  • No performance impact whatsoever. (When using WASAPI and ASIO, or DirectSound with the old buffer mode disabled.)
  • Way less demanding minimum requirements than BASSMIDI Driver and CoolSoft VirtualMIDISynth.
  • Many customization options, compared to its sister-like synths.
  • MT-32 mode that allows old DOS games or MT-32 specific MIDI to play properly.
  • Temporary voices limit burst if there's enough rendering headroom
  • Supports the MIDI Stream API


  • Doesn't use the PnP service to register itself as a user-mode driver, and as a result has issues on Windows 10 build 2004 or newer.


Special functions[]

  • People can change between soundfont lists by pressing CTRL and a number from 1 to 8 (CTRL + 1 = List 1 etc.)
  • Able to achieve near 1ms latency by using the ASIO engine.
  • All apps without native KDMAPI support on Windows 10 must be patched with the integrated WinMM patch to dramatically improve performance