I'm with guest leenia. I also don't understand what homeschooling has to do with this.
There is no legitimate reason to start pushing kids into playing an instrument at such young ages, except the mania of the parents, in my experience. You are just forcing them to play the instrument YOU want them to play.
Now, that is not to say you shouldn't be doing musical activities with your kids. We sang our way through the day, just making up sing song, adapting songs we knew and on the spot made up new words for, that sort of thing. The language skills are so much more important at this age, and singing the most natural music activity that supports that for very young children. Other than that, we banged on, hummed on, strummed and clanged on anything and everything. We spent some serious money on music stuff over the years. Maracas, small drums, xylophones, keyboards, bells (really cool and the kids loved that one--for a max of about 5 minutes), the floor, the pans, the kazoos, the mouth harp, a bazillion flutes/whistles, and our all time fave, the rain stick.
Children need to explore at an early age. They'll learn what they want. They'll get the singing drills soon enough in school and church, if you put them in those classes.
I have friends who homeschooled their kids, and once they were old enough to start lessons, around age 8, they NEVER taught them. Put them in lessons with music teachers, for social and emotional reasons. Homeschooled kids should absolutely NOT be locked up excluswively with their parent-teacher. It has a very negative effect on their long term social development. Homeschooled kids need contact with other kids outside the home, and in an environment where the parent-teacher isn't in control. My friends who homeschooled regularly enrolled their kids in classes at places like the Science Museum, music classes, drama classes, art classes, dropped them off at the library for story times, that sort of thing.