YOU SAID:

I'll play the song that i wrote for you today

INTO JAPANESE

今日あなたのために書いた曲を演奏します

BACK INTO ENGLISH

I'll play the song I wrote for you today.

INTO JAPANESE

今日は君のために書いた曲を弾きます。

BACK INTO ENGLISH

I'm going to play the song I wrote for you today.

INTO JAPANESE

今日は君のために書いた曲を演奏するつもりだ。

BACK INTO ENGLISH

I'm going to play the song I wrote for you today.