שִׁ֣ירוּ לַ֭יהוָה שִׁ֣יר חָדָ֑שׁ שִׁ֥ירוּ לַ֝יהוָ֗ה כָּל־הָאָֽרֶץ׃
זינגט צו גאָט אַ נײַ געזאַנג, זינגט צו גאָט, די גאַנצע ערד.
Rashi
a new song This song deals with the future, as is proven by the final verse, “for He has come to judge the earth.” Any reference to a “new song” deals with the future.