You can play C instead of C6 to make it easier however this results in it sounding "happier" than the original. Partly this is because reverb and bass used by Jamie convey a melancholic feeling in themselves but also because at some part you hear a line of single notes alternating between an a and an g. Therefore the Chord would actually jump between C and C6. Same goes for F and Fmaj7 and Am and Asus2. Video source: https://www.youtube.com/watch?v=S-C-pOR6QP4 [Intro] x6 F C6 Am G (With you) (With you) [Chorus] F C6 Am G On a seesaw Up and down F C6 Am G On a seesaw Up and down Up and down with you F C6 Am G On a seesaw Up and down F C6 Am G On a seesaw Up and down Up and down with you [Verse 1] F C6 Am G I see pictures in my mind (With you) (With you) F C6 Am G I see fingers up my spine (With you) (With you) F C6 Am G I saw my heart break in two (With you) (With you) F C6 Am G I saw her again with you (With you) (With you) [Chorus] F C6 Am G On a seesaw Up and down F C6 Am G On a seesaw Up and down Up and down with you [Same as intro] x6 F C6 Am G (With you) (With you) [Verse 2] F C6 Am G I can see it your eyes (With you) (With you) F C6 Am G I see through your thin disguise (With you) (With you) F C6 Am G She was always my best friend (With you) (With you) F C6 Am G I saw you with her again F C6 Am G I see pictures in my mind F C6 Am G I see fingers up my spine F C6 Am G I saw my heart break in two F C6 Am G I saw her again with you (With you) [Outro] F C6 Am G (With you) (With you) F C6 Am G F C6 Am G F C6 Am G [Voices] N.C. Just stuff.. N.C. I just.. N.C. The world just.. N.C. I just..
Source: https://tabs.ultimate-guitar.com/tab/jamie_xx/seesaw_chords_2596044