I'm pretty sure that NobodyNada knows this, but for pedants out there using Bb instead of A# is specifically a classical European music notation thing.
There's nothing wrong with using A# and plenty of other notations do. For a modern, hacker-y example, tracker notation only uses sharps).
There's nothing wrong with using A# and plenty of other notations do. For a modern, hacker-y example, tracker notation only uses sharps).