Time Machine recovery after system re-install

After a series of problems I took my iMac's advice and erased my hard drive and re-installed the operating system. I have a series of backups with Time Machine on an external drive but cannot recover them with my new OS installation. Any chance I'll see those thousands of photos and hear all that music again? Any help much appreciated, there's not many Mac experts here in Orkney.

have you tried running the migration assistant in Applications / Utilities

What happens when you try that?

On another point, you dont know anybody called Houston in the area by any chance?

Time Machine recovery

Thanks for that, unfortunately Migration Assistant is not recognising my external drive.
By the way there's a Houston lives on Shapinsay.