I just play F, C, Em, and Am throughout the entire song.
F C
You had my heart and we'll never be world's apart...
Em Am
Maybe in magazines, but you'll still be my star.
Same chords...
F C
'Cause I'm singing in the rain, just singing in the rain
Em Am
What a glorious feelin', I'm happy again.
F C
I'm laughing at clouds so dark up above.
Em Am
I'm singing-singing in the rain. 