i haven't listened to Rydah or Tequila, but I'm playing them in my head. i've never put the two together before, but i can hear the similarities; Rydah sounds like portions of Tequila slowed down (it's pretty obvious once you think about it). i'm at work so i don't have the AEOM book in front of me, but does it say if it's a sample or an interpolation. it could be either, but Rydah sounds like a piano, and i'm pretty sure Tequila isn't, so it's probably an interpolation.