There is a ton of music that is available on the internet from musicians and composers who are trying to make it this is where I have gotten some of my music from. Look in the sound section on this forum and you will see many composers have posted offering there work to video makers. If you like the sound of someones work just send them an email explaining your project if they are interested in the project then great if not move on to the next one. Just spend a bit of time on Google searching for royalty free music, There are lots of sites that offer very reasonable licences like AKM Music there licence is very good and you can get a track for around a tenner or even less. There are film soundtrack style CDs as well as individual songs.
Another source is to look at your lock music scene. I'm sure in Edinburgh there is a healthy music scene with lots of local musicians who would be interested. Get down to some pubs and venues to check some out. That should enough info to get you strated.