Standard (EADGBE)

 First time I saw her she was standing in line,

 Holding a book about compatible signs,

 I should have talked to her, I should have tried,

 But I was breathless by the look in her eyes,

Then gentely slide back open

You repeat the same thing through all the verses AND chorus's

 If you see Kate tell her that i’m looking for her,

 She’s so fine,

 That girl's been on my mind,

etc.

The only time it changes is when he does the weird bridge thing at the end, it changes to

  finish with an open

She's been on my mind

..

It really is quite simple :)