The gig poster problem, solved
Music discovery happens in places where typing is impossible: a dark venue, a flyer handed over at a show, a sticker on a lamp post, a merch table with a queue. A QR code is the only realistic way to convert those moments, and it's why they've become standard on posters and demo packaging.
Point it at your profile rather than one track. A release code is dead the week after the release; a profile code keeps sending people to whatever you've put out most recently, which is what you want on a sticker that might sit on a laptop for two years.
Print big and print dark. Posters are scanned from a few steps away, which means the code needs to be a decent fraction of the sheet — as a rough rule, about a tenth of the distance people will stand from it — and high-contrast, because venue lighting is rarely on your side.
Every SoundCloud code made here is static: the link lives in the pattern itself, with no redirect service in the middle that can expire, start charging or go down. There's no account, no watermark and no scan limit — download it once and it keeps working for as long as the SoundCloud link behind it does.