You don’t need to be able to read sheet music to be a musical genius. It can’t hurt, but if the long list of influential musicians who couldn’t read a note of music is anything to go by ...
The style of singing in a musical is very pop/rock and will include syllabic and melismatic word setting: To make a word sound confident and clear the music will have one note per syllable.
Icelandic photographer Haukur Sigurdsson took a fantastic photograph at the Fossavatnsganga ski marathon depicting a group of cross country skiers who happened to look like notes on a musical staff.
An opera is a musical play performed on stage with costumes ... Syllabic word setting is when a composer uses one note per syllable in order to make a word sound confident and clear.