Grammar check for a 7-year-old: Fixing 'The pigeon softly COOS, and with everybody singing It becomes like a little animal concert.'

Corrected sentence (small fixes):

The pigeon softly coos, and with everybody singing, it becomes like a little animal concert.

Another simple way to say it:

The pigeon coos softly, and when everyone sings, it becomes like a little animal concert.

1. COOS → coos: We don’t use all capital letters in the middle of a sentence. Use normal lowercase letters unless it is a name or the start of a sentence.
2. It → it: Don’t start a new capital letter in the middle of a sentence unless it is a name. So make 'It' lowercase.
3. Comma after 'singing': The piece 'with everybody singing' comes before 'it becomes...'. Put a comma after 'singing' to separate that little phrase from the rest of the sentence: '...singing, it becomes...'.
4. Word order (optional): 'The pigeon coos softly' sounds a little more natural than 'The pigeon softly coos,' but both are okay.

Nice sentence — just small punctuation and capitalization fixes!