Americans behind bars try bottles right on top of shelf after measure of ale (9)

'americans behind bars try bottles right' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'top of shelf after measure of ale' is the wordplay.
'top of' indicates taking the first letters.
'after' says to put letters next to each other.
'measure' becomes 'yard' (yard is a kind of measure).
'of ale' becomes 'bird' (I am not sure about this - if you are sure you should believe this answer much more).
The initial letter of 'shelf' is 's'.
'yard'+'bird'='yardbird'
's' put after 'yardbird' is 'YARDBIRDS'.

'on' is the link.

Can you help me to learn more?