Still have an earlier version of the same case. It's solid, rack mountable and is decently laid out for that form factor. The processor/RAM/heatsink/B550 MOBO combo is decent too. The NVME boot drive is probably a little smaller than I'd like in an ideal world, but 500GB should be fine if it's actually going to just be for music production (if they can up it to 1TB size without costing the earth, do so). The cooler is decent enough and should keep it on the verge of inaudible, which is always nice.
There is a 1TB Seagate Barracuda listed as a storage drive on the front page description, but it's not listed on the specs page. That should be checked on as to whether they include it or not, if they do, the price difference between the 1TB version they listed and a 2TB version of the same drive is a tenner. If you're going to actually go for a regular HDD, spend the extra tenner and get the 2 TB version.
What I'd recommend rather than that though is putting a bit more $ in and getting a 1-2TB SSD for storage, more expensive, but no drive sounds means less distractions/background hum when you're working (the HDD is likely to be as loud if not louder than the CPU cooler when doing seeks/writes). It doesn't need to be expensive or particularly fast as a storage drive, just ask them for a 1 or 2TB Samsung QVO and you'll get something fast enough and utterly silent.
The graphics card is anaemic, but it will do the job for any music prod software and allow you to stream video etc. In the current market, that's pretty much all you can get without bumping the price of the whole build up another £400 for something that's even then, low end. Don't waste money on a better card for now unless you really want to play games now, prices should start to fall on GFX cards in a few months time and if you really want a card that can do more, spring next year (Q1/Q2) should see prices start to fall properly. In the meantime though, prices are outrageous for them and retailers barely have any in stock.
Seasonic PSU is excellent and will be absolutely silent at 30% or less power draw, which should be most of the time if nothing else power hungry gets added to the machine.
I priced it all up off the same kit listed on their website and so long as the 1TB HDD is included it works out to roughly £1179-1199, plus call it a hundred for them assembling and setting it up for you while you also don't have to wait for a GFX card to come into stock, that would bring it up to their asking price of £1299. It's not a bad deal if you want it assembled for you, plus Scan are good at looking after you if you do have problems down the line.