MUSIC THEORY
There are some really useful theory videos at musicteacher.co.uk
Alison Sparrow has recorded some really helpful YouTube music theory lessons:
Beginner theory Grade 1 part 1 https://www.youtube.com/watch?v=F86tvYhy0o0
Beginner theory - Grade 1, part 2 https://www.youtube.com/watch?v=unsXNUsn5Xg
Grade 2 theory - https://www.youtube.com/watch?v=FQJA_sjXh20
Grade 3 theory https://www.youtube.com/watch?v=6FGEZsf9PHA
Grade 4 theory https://www.youtube.com/watch?v=TqtMAmaTcfY