THIS is the ONE, if you must have only one MIDI FX. It's got pretty much everything and goes way beyond "just" the 5 great sequencers. There's also MIDI Thru (BRAVO!!), a bushel of great modulation types for both self and MIDI CC modulation, and its own internal rack of 9 other MIDI FX, like keyboard transposing, scale filtering, etc. State of The Art, 2019—VERY well done.
This cool cross-platform MIDI FX offers the best application of Euclidean beats to melodic, tonal material I've yet found, because it has two arpeggiate modes, which loop whatever notes you hold through however many tracks you've got set to arpeggiate. Other tracks can be set to any specific note, or to play a held chord, or to send MIDI CC. I just posted a video demo of all this in the topic here: https://www.kvraudio.com/forum/viewtopic.php?f=6&t=517113&p=7474380#p7474380
Apart from this killer feature, the plugin is about as rudimentary as it could be: No presets or saving, no rotating of tracks to offset the pulses relative to other tracks (only reason I docked it a star—REALLY hope they add rotating!), but in exchange it's super simple and elegant, and dirt cheap! I've got a lot of other ways to implement Euclidean beats, but this is so far my favorite because of that brilliant arpeggiate feature, which of course is just as cool on drum kits. It makes interacting with the beat totally fun and powerful.
I'm a big fan of MIDI FX and devices (arps, sequencers, randomizers, transposers, etc.), and have bought pretty much everything in these categories from HGSounds, thanks to their very generous Group sales, which includes a ton of fascinating Kontakt-scripted MIDI FX; they're all delightful, musical, and OTT deep with well thought-out features. This is right in that category, but at the same time completely different, as this one only MANIPULATES and VARIES MIDI content that the user supplies; it doesn't GENERATE it from scratch. So far, this has meant that the MIDILooper, for me, is the most fun of ALL the HGS MIDI offerings. It's the one that feel most like a performable instrument and least like a machine I simply set in motion and tweak a few parameters while it rolls along. I LOVE IT! Thank you, Andrew [the HG dev].
Well, clearly some are going to just gag at the endless depths of this no doubt most complex EVER Melda creation (see thread here, where the fans and the gaggers fight it out: https://www.kvraudio.com/forum/viewtopic.php?p=7400187#p7400187), but if you're delighted by complexities, the madder the better, THIS is your newest thrill! It's certainly mine.
There's already plenty of info and help, much response from the dev in his own forums (https://www.kvraudio.com/forum/viewforum.php?f=138), new presets and devices being posted and Exchanged... as well as it being also still a beta, which is explorable for free with all functions on. Pretty much EVERY other Melda product is included inside it, including MPowerSynth and MXXX, all the sounds from MDrummer, a healthy selection of new oscillators, heavy on the PModeling, plus WT and FM, and they can all be patched together in infinite ways... So, while it's still at 66% off..."Bargain of the Year", or even "Decade" barely covers it, imo.