I once own logic pro 9 on disk. Now I have a laptop that doesn't have a disk drive. I want to get back into music producing. What do I have to do? buy the software again?

Totally agree with the two replies above.

Just a little correction: if you still have Logic Pro 9 installation DVDs, all you need is any portable DVD-drive to install it, not necessarily Superdrive. Also, if you have a powerful enough Mac, you can run a legacy Mac OSX (and LP9) in a virtual machine, using VM software like VirtualBox, or similar.

That being said, though, it's totally worth it to switch to current Logic Pro. It costs less and packs more. I personally like the new genre-oriented loop packs. Plus, it allows to download all legacy sound content for compatibility with projects created with earlier versions.

To use Logic 10 you would need to buy the software again.

But to use Logic 9 I guess you need a Superdrive to install it from the CDs, bearing in mind that Logic 9 will not function on the latest OS, I believe El Capitan was the last compatible OS.

Good luck, i know a few people who swear by Logic 9.

If makes any difference, everyone who went from 9 to X had to buy it.

As we did from 8 to 9, 7 to 8, 6 to 7 and all the way back.

It does now cost less to buy it outright than it used to upgrade.

There have been no further costs once Logic X was purchased. That's no additional cost since 2013, which is pretty cool.