One calling that is quite important is that of Primary pianist. Although this calling may seem peripheral to the Primary organization, it really is an important calling. I have served in a Primary presidency when we had an extremely difficult time finding someone to be the pianist. If you are serving as the pianist then you should realize that your calling is essential in helping the Primary children learn the songs.
It is important to practice and prepare to play the songs that the children will be singing each week. If you feel that you do not play well enough to accept the calling, pray carefully about your decision. Sometimes just having the melody played is enough to help the children learn the songs. Also as you sincerely practice, the Lord can help improve your playing as you are serving in the church.
The pianist can work with the chorister in choosing songs or arrangements for the Primary program. Additionally the pianist provides a wonderful atmosphere as he plays both prelude and postlude music. The pianist can also serve as an example to the Primary children. The children love music and a good pianist (enthusiastic and happy to be there) can really help them to keep this love.
Additionally, primary leaders may encourage younger primary children to practice to play certain songs for the program. This can help to prepare future primary pianists as well. You may also consider learning as an adult, because it is a skill that is highly needed. I know of one father who taught himself to play the piano while he sat and waited for his children during Seminary.
It is important to recognize and give thanks to those who do serve as pianist. It takes time during the week to practice the songs, as well as the time spent in Primary every Sunday. It truly is a skill to play as an accompanist.