mylifemykids my DS1 sounds similar to yours. My DS learnt to at 3 through osmosis** (LOL) We would have story time at night and his older sister would read her story book from school first (she had only just started school) She stopped to cough or something and DS who was arranging his toys on the bed behind us looked over her shoulder and said its "the" true enough that was the next word we were . A day or two later I was writing a shopping list whilst DS was eating his breakfast he looked over the table and said "can I choose the oranges?) I had written oranges on the list the night before. He had read the word. IT took off from there and I was actively discouraged from "allowing" him to continue by his pre-school. Who some months later admitted that all DS did was sit in the book corner all session whilst the other children were running around etc
School was only a problem in the beginning because they don?t rush them into reading and were doing letter sounds so he was bored but never disruptive (just wanted to stay with me) Once the head teacher saw him screaming she asked why and sorted it all out he was allowed to pick the first reading books to bring home (he used to choose anything between 4 and 7)
My DD was at school so I was able to mention his reading to the Head who was lovely, didn?t discourage just asked me to check he understands what he is reading.
**I say he learnt by osmosis because he just seemed to absorb the knowledge through listening to his sister learning to read. DS has always been bright and always been at the top of his class but he isn?t competitive (Doesn?t feel the need to win at everything, or be better than anyone else) he still finds school work easy and still doesn?t feel the need to let everyone know so he coasts through school not really having to try too hard.
Sorry a long post hope you made it though it.
My advice FWIW would be I would carry on as you are, enjoy reading books with him. Talk about that he thinks might happen next if he would like to (some little ones don?t like to do this, so don?t worry if he doesn?t want to), make up stories (we would do mini stories whilst in the bath or in the car etc), act out familiar stories.
Do activities based on stories (after reading the Gingerbread man together we made and decorated gingerbread men cookies. After reading about a teddy bears picnic we got out the play dough and made a pretend picnic for his toys.)
My DS loved music too. We would go to a music group once a week (music with mum type thing; where we (mums and tots) all sat around and all joined in with the rhymes and songs. DS would never sing whilst there he just sit and listen then he would sing the songs on the walk home, in the same order we had sung them in.
We didn't do just reading or book/story activities we did all the the normal things to: park, swimming, playing games, in the garden, soft play, messy play, watching tv, housework! LOL He was not hot-housed or pushed in anyway.
Sorry it was so long but hope it was of some help to you.