[This is a Sample application format to the principal to participate in a singing contest or activities. You can follow this request letter to participate in a singing contest to show your talent. You can modify this formats as your requirement.]
Sub: Application for Participating in the singing contest
I hope this application will find you in best of your health. I am a student of (Subject name and department name) in (class/semester number) in this college/university. I am an all-rounder as I work both in studies as well as in Co-curricular activities from school to my college/university life. I know a healthy body has a healthy mind. So I always work for studies and entertainment too.
Entertainment is an essential part of our life so I choose singing as my hobby. I want to participate in Colleg or University competition and Singing activities of the class. I am good in singing as I attended the classes of singing and I know singing notes too. I want to Compete for all universities and bright the name of my college/university. So humbly request you to give me permission for this activity. Please support me in this decision.
I hope you will consider it and allow me. I am waiting for your response in this regard.