This is a big bug bear of mine.
My DDs had virtually no class music lessons- a bit of singing for school plays (not every year) and half a term of recorders in year 4.
Neither of them laid a hand on so much as a tambourine for the four years they were there. There were no opportunities to compose or peform on tuned or untuned percussion instruments and the school orchestra was full of children who had private lessons (and this is what OFSTED saw so naturally they though the music was outstanding...) I complained about it every time we were sent a parent questionaire.
I am a music co-ordinator in a regular common or garden Junior school. Many of our parents can't afford private lessons but there are some amazingly able children- why shouldn't they have the opportunity to develop their skills?
All of our pupils have around three quarters of an hour to an hour music lesson per week.Our year 3s learn the recorder, Year 4s have guitar lessons (with a visiting specialist) Years five and six follow two music schemes which have have activities which include the use of instruments and singing- they are perfectly easy to follow for the non-specialist.
None of the class teachers in my school are music specialists but they all give it a good go. It is perfectly possible to differentiate music activities for a wide range of abilities.
We have a school choir, recorder groups, a brass club, a ukele club and a school orchestra which comprises some children who have lessons, some from the recorder groups and some who have been spotted in their mainstream lessons as having potential.
Schools wouldn't not do Art, PE or DT-Why is music so often maligned and ignored- it is a part of the curriculum that should be taught every week.