You have such a beautiful voice and the song is beautiful too.
What an amazing voice you have and the song is really nice too!
この場合、次のような言い方ができますよ。
ーYou have such a beautiful voice and the song is beautiful too.
「あなたの声はとても美しくて、歌もとても素敵です」
ーWhat an amazing voice you have and the song is really nice too!
「なんて素晴らしい声をしているの!そして歌もとても素敵です」
ご参考まで!