Diary entry - Since last year, my neighbour upstairs

[Maybo]

This is an entry from my diary. Please check it and correct any mistakes.

Since last year, my neighbour upstairs has been playing the piano frequently. Sometimes, it's very annoying because he would play loud fiery music. Our building isn't well soundproofed so every time he practises, it sounds like I'm living next door to him. However, I think I'm getting used to it. Now, when I hear my neighbour starts to practise, I might have a coffee and pretend that he performs for me exclusively. I can recognise one of the repertoires he/she usually plays. It's a soundtrack from an local anime. I like to sing along when I hear it.

 

[emsr2d2]

This is an entry from my diary. Please check it and correct any mistakes.

Since last year, my neighbour upstairs has been playing the piano frequently. Sometimes, it's very annoying because he [STRIKE]would[/STRIKE] plays loud [STRIKE]fiery[/STRIKE] music. Our building isn't well soundproofed so every time he practises, it's [STRIKE]sounds[/STRIKE] like I'm living next door to him. However, I think I'm getting used to it. Now, when I hear my neighbour [STRIKE]starts[/STRIKE] start to practise, I might have a coffee and pretend that he is [STRIKE]performs[/STRIKE] performing exclusively for me. [STRIKE]exclusively.[/STRIKE] I [STRIKE]can[/STRIKE] recognise one of the [STRIKE]repertoires[/STRIKE] pieces he [STRIKE]/she[/STRIKE] usually plays. It's [STRIKE]a[/STRIKE] from the soundtrack to from [STRIKE]an[/STRIKE] a local anime film/programme. I like to sing along when I hear it.

Note my changes above. You said "he" in sentence 2 so it doesn't make sense to use "he/she" later on.
I don't know what "fiery" music is supposed to be.
Saying it's like living next door to him doesn't really make sense. If he lives directly above you, you sort of do live next door to him. In fact, I would expect to hear more noise from an upstairs neighbour (in two flats) than from someone in the house next door. You could say that sometimes it feels as if you live in the same flat.
His repertoire is the entire collection of pieces he plays.
I don't think "local" is really what you mean. That sounds as if it was filmed in your local neighbourhood/area.