For quite a few years I've wanted to get my Mum into the world of "what happens if you connect the piano to a computer". To get this goal off the ground, I've invested in a MIDI interface box and a 2013-era iMac - a little on the older side, but I understand OS X (so named in the versions ideal for this hardware) is the king of music production and latency, and so hopefully this hardware represents an above-adequate start. Ideally it will be replaced in a small handful of months.
So, I've got a keyboard, a MIDI box, and a Mac - but I have no idea what audio software to get Mum started with!
OS X/macOS will be enough of an adjustment on its own (from Windows, and a stint on Linux), and I know dropping Mum into a MIDI sequencer will be utterly foreign, alien and disillusioning. Before Mum absorbs "MIDI sequencing" generally, she'll go through a period where she calibrates off of the idiosyncrasies of whatever software she's saddled with.
I remember when I was in a similar position myself, just after discovering QBASIC on the 386 I was playing with at the time. I unwittingly internalized a dumbed-down ideological model of computing that QBASIC exposed as ground truth as I didn't know any better, and I only later realized it was reasonable that I failed to see beyond the simplified horizon that was presented and grok the fundamentals of programming because what QBASIC presented felt pretty "complete" at the time. That took a good decade to unlearn. I do not want Mum to fall down a similar hole of "local maxima", so I want software that is not simple and is not dumbed-down, but instead represents diving in at the deep end, drowning for a bit, and (eventually) surfacing with a firm foundation.
The above represents my predominant concern about the type of software I'm looking for, alongside a broader set of considerations:
<$200, ideally <$150 (FOSS and/or free would be an unanticipated bonus)
Indefinitely licensed (for the version purchased)
Will run reasonably performantly on a 2013-era iMac (perhaps I can get an older version second-hand), even if suboptimally configured, and loaded down with a few plugins
Expressive instead of simple
Consistent instead of intuitive
Emphasis on getting out of the way of (eventually) confident sequencing/production, as opposed to simplification/dumbing-down/new-user onboarding
Primary focus on MIDI sequencing, with reasonable support for sampling (to capture the sound of the keyboard's synth, if Mum wants to do that - I also have a USB audio box)
I'm curious to know about *both* sides of: relevant/mainstream vs obscure/idiosyncratic
As you can see, I have exactly no idea what I'm doing :) in terms of domain-specific knowledge about sequencing/sampling/mastering - I have a cursory/broad understanding of the terms, but haven't gotten to the points I describe above for myself yet, so I can't pass them on. Hence, I really really appreciate any advice that can be offered here.