Serato DJ Pro 2.3 is here!
This release gives support for macOS Catalina. Apple’s new ‘Music’ app is also supported which provides a seamless transition for DJs. 🔥
— Serato (@Serato) October 21, 2019
However that’s not everything you’ll need to control the music, and Serato has a list of hardware that’s either compatible with Apple’s latest software, in testing, or unsupported, and you’ll want to double check that before updating or buying a new Mac. Also, as The Verge notes, some other DJ software like Rekordbox has not yet updated to work with Catalina, so make sure you have a full accounting of things needed for a day (or night) behind the decks.