S3: Over You - Cassadee
S4: Sad - Amber
S5: Bridge Over Troubled Water - Tessanne
S6: Can't Help Falling in Love - Christina
S7: I Walk The Line - Craig (But really Masterpiece by Chris and Jessie)
S8: Make it Rain - Koryn
S9: Somebody to Love - Jordan
S10: I'm Sorry - Adam
S11: Nothing (I guess "Me & Jesus" for pure entertainment value)
S12: Nothing
S13: Tennessee Rain - Addison
Haven't really watched any full seasons after that.