from Marvin Gaye's masterpiece album What's Going On, the song is Mercy Mercy Me (thing's ain't what they used to be).
You want to know what those 2 sweet power chords are at the beginning of the song (because they create such beautiful tension):
Transpose your keyboard to -8 (or -9) so you'll be in Marvin's key of the song (pls don't ask me what key that is). It's always nice to play in the same key as a famous piece of music (it creates a sympathetic vibration in the ear of the listener which is pure magic).
The first power chord is: F# bass notes and Emaj treble notes
The second power chord is: G bass notes and Fmaj treble notes
The key of the song is Cmaj, with the first chord of song being Cmaj7
the rest is history you can play by ear.