I tried editing my config.yml as the guide suggests but the problem persists. The problem seems to be that I’m using MariaDB instead of MySQL (pdo_mysql is compatible with MariaDB). Is there anything more I can do or should I try installing MySQL?

EDIT: Purging MariaDB (Debian repo ships this instead of MySQL) and reinstalling it with sudo apt install default-mysql-server fixed the problem. Thank you.

Renoise is an excellent tracker-based DAW with Linux support (you still have to find Linux-compatible VSTs though). It changed the way I write music.

EDIT: I know there are FOSS trackers like MilkyTracker. If you want an alternative, I can recommend it, even though it doesn’t offer the same amount of features as Renoise (e.g. VST or effect support).