Sure you know the Bliptronic5000^® or the Tenori-On™. If the first one lacks MIDI and the second one is too expensive for you, you might try this VST-version of a matrix stepsequencer:

Blip2000

(click image to enlarge)

Every column corresponds to one step, each line represents a note. Just click the buttons to enable the notes to be played. The orange line runs thru while playing. Select the number of steps to play (2-16), the speed in relation to the host clock, the direction (forward, backward, random etc.). Blip2000 outputs MIDI notes, so you can use your favourite synth (-plugin) as the sound source. MIDI channel, note length and velocity can be set.
With the fields on the left side you can adjust any scale to be played - or use Blip2000 as a drum sequencer!

Features:

clear and easy interface number of steps selectable (up to 16) note per line selectable from 3 octaves with display several play modes (forward-backward, random etc.) syncs to host - clock divider adjustable sequence transpose by MIDI input MIDI ouput channel selectable automatable in the DAW sequences can be saved as VST plugin presets random play MIDI-ouput; any plugin or synthesizer can be used as sound source low on CPU free ! (only limitation is a nagscreen at the start)

Available for Windows PC as VST-plugin. You’ll need a standard host program that sends correct VST sync information.

Download now. No installer, no copy protection, just place the .dll file in the plug folder of your favourite DAW.

Go to mainpage to download.