Yeah, so in theory, that would be equivalent to 3 a-levels, which is perfect. Check with your college, as there may be a timetabling issue, but you should be fine.
I really enjoyed btec music. I did the a-level too, so the btec was a really good opportunity to focus on performance, which is one of the things I'm planning to focus on at uni (the a-level got me really into theory and 20th century music, which I'm also planning to focus on at uni).
Both years we had a solo and ensemble performance, and then also had extra stuff to do as well, such as popular music history, which had a performance and essay, we had to organise a gig and then also had a unit on the music industry, which is the only one we did where there was no performance/practical at all.
I felt it was really beneficial to do, especially if you're more into performance and practical than theory. Obviously whether it was 'worth taking' will vary from person to person, but I felt it was great and also quite easy to do well in. I got a Distinction and only ever got really stressed at the music industry unit.