To be a doctor you do, generally As at A levels and good GCSEs. Have a look at a Uni admissions page for what each one requires.
If you’re from a single parent family, had free school meals, are the first to go to uni etc then you can sometimes get involved in outreach programmes where you can get interview practice and sometimes lower offers – have a look at your local Uni/medical school website 🙂
Cat ( Music Therapy): For music therapy you need to be at a professional level of musicianship on at least one instrument and preferably have a music degree or psychology degree but this is not essential. Sometimes people come to train as a music therapist after doing something else for a while ( e.g. teaching). There is an emphasis on emotional maturity to be able work with people with complex needs and your ability to be empathetic rather than just focusing on your grades. The training is at Masters degree level so you do need to able to articulate your work and communicate what your aims of therapy would be and why. Research is also an element of the training so there is a long thesis to complete.
Steven here, the better the grades you get will help you to start your career in a more straight forward/traditional way but the NHS is open to all sorts of recruitment including apprenticeship and all post have lifelong learning opportunities and good training packages. It is very common for people to change roles and get promotion following more training.
I’ve seen some people who didn’t do well at school go into medicine, and many actually make better doctors than the ones who have good grades. There are ways of getting into medical school if you don’t get the required A levels, but it may mean doing an extra year before medical school (called pre-med). This is how it used to work when I did it, and it may have changed since then so it is worth asking a career’s adviser about this. When I was at school I used to think it was all about grades, but when you get into university you realise that try few people care what grades you got, and you never get asked about them after that!