I can't speak for higher grades, but I've got a child in 1st grade public school and they seem to spend a disappointingly small amount of time on fundamentals. They did waste a good 20 or so hours over the past few weeks rehearsing for a really awful music performance that most of the kids appeared to have cared less about.
Besides the evidence that math skills are improved by music exposure, I'm going to assume that your kid doesn't spend this much time on music practice during the entire school year. Special circumstances do come up in life.
My son is in 1st grade as well. His day:
8:30-9:10 Phonics and Calendar (math based)
9:10-9:30 Recess
9:30-10:30 Reading groups
10:30-11:00 Whole group reading
11:00-11:25 Lunch
11:25-12:00 Writing
12:00-12:20 Recess
12:20-1:30 Math
1:30-2:30 Specials (PE, Music, Library, Computer/Guidance)
2:30-3:20 Social Studies/Science
tl;dr A ton of fundamentals