I play multiple musical instruments, and was part of a football team for many years. Are these skills/qualities that I should be putting on my CV, or is it just a waste of employers time?

These are a good thing to put on your CV and to be included in your answers in applications too. Its good to have hobbies, especially ones that relate to the work you want to do. Think about the skills you've gained from these hobbies. Its good to have evidence for where you've used certain skills that would be valuable for an employer. For football, have you gained teamwork, communication, ability to think under pressure? Playing instruments proves you are committed to learning things that take time and you can stay motivated even with difficult tasks.

Just to build on what Alice said, I would have small section on your CV for 'hobbies and other skills,' to include your musical instruments, team sports, things like your drivers license too.