Learning the names and functions of musical notes, both written and in musical notation, can help secure a strong musical foundation for any child.
Being able to recognize key signatures on a written page of music is an essential skill for any young musician to have.
While playing the notes is important, playing them with the proper rhythm is also just as important. Being able to count and play a piece, and to recognize the different rhythms on the written page, will greatly improve a child's musical skills.
Since the piano is one of the most visual instruments, and one of the most popular, it is a good starting point for a child to begin exploring music. Many famous musicians started on the piano and then branched off to other instruments later in life.
Learning to sing, and especially sight-sing, can be a fun way to expose a child to music. Singing can be done as a soloist or in a choir, or other vocal ensemble, which also exposes the child to other musical elements such as blending and dynamics.