They always play jazz music, so the atmosphere is nice.
You always hear jazz music in their shop, so you feel good when you're there.
この場合、次のような言い方ができますよ。
ーThey always play jazz music, so the atmosphere is nice.
「いつもジャズをかけていて、雰囲気も良い」
to play jazz music で「ジャズをかける」
atmosphere で「雰囲気」
ーYou always hear jazz music in their shop, so you feel good when you're there.
「店ではいつもジャズが聴けて、店にいると気分が良い」＝「いつもジャズが流れていて、素敵な気分になれる」
ご参考まで！
There is always jazz playing and its a really nice atmosphere.
"いつもジャズが流れていて素敵な雰囲気なんだ"
- There is always jazz playing and its a really nice atmosphere.
- There's always jazz playing and a great atmosphere.
- There is always jazz playing there and they have a really nice atmosphere.
カナダ 
アメリカ合衆国 
