I have the B-450 Tomahawk in my system; it was my first DIY build a couple of months ago. IMO, it's a solid MB, but the onboard sound chip could be better. If I'm taking you correctly and you're looking at serious music recordings, I'd get that sound card sooner rather than later for the sound quality alone.
Also, the RX 480 may be a bottleneck...not totally expecting it to be, but at least keep an eye on it, depending on the game of course. However, I did an upgrade from an FX 8350 to an R5 1600 and I did notice that the stutters that I used to have on World of Warships and Cold Waters went completely away when the 1600 was running the show while transferring my RX 580 8GB (Red Devil Golden Sample). So like I said, not totally expecting it as the 480 should still run you pretty well. Just something to keep in the back of your mind.
Also...the BIOS that comes with the Tomahawk (or at least on mine) is dated 3/6/19 (MSI BIOS version 7C02v17 ), and seems like it could be pre-Ryzen 3000 (see further down for a little more on this). Depending on where you get it from, see if you can get store assistance in upgrading the BIOS (or at least get their opinion on the description (upcoming) and having it tested/in place before installing the 3600, else the board may not be compatible on a BIOS level (BIOS description on their site says, "Support new upcoming AMD CPU", which to me says it might be compatible...but not entirely sure regardless). Be advised that there are still voltage spike issues going on with the 3000 series, and I haven't seen much (if anything) addressed through the YouTube reviewers regarding that issue...only that the boost clock fix seems to be running decently; though AMD is pushing out a new BIOS to vendors, those vendors still seem to be in the process of integrating it with their own BIOS/chipsets. Even AMD hasn't published the new version just yet. MSI has an updated beta version right now but even they recommend to not install that BIOS version unless absolutely necessary. Just this past weekend, I pulled the trigger on the 2700x knowing full well it's a little short of the 3600...but to me, that voltage spike issue triggers my paranoia as it can spike up to around 1.5 volts at idle, and the max anyone recommends is 1.45 volts. AMD claims that those spikes are so minimal that it won't damage the motherboards...but with the 2000 series not having these issues with BIOS', I personally took no chances. (Besides...that cooler is PRETTY...lol).
I'm really not trying to steer you away from your choice...just some things that you may need to know in advance.
Good luck, and have fun on the new build!