[This](http://www.d20pfsrd.com/feats/general-feats/spellsong/) is the feat in question.

> 
> You can conceal the activity of casting a bard spell by masking it in
>  a performance. As a swift action, you may combine your casting time of
>  a spell with a Perform check. Observers must make a Perception or
>  Sense Motive check opposed by your Perform check to realize you are
>  also casting a spell.
> 
> 
> 

With the way it's worded, and the way [versatile performance](http://www.d20pfsrd.com/classes/core-classes/bard/#TOC-Versatile-Performance-Ex-) is, can one feasibly use perform (act) while using spell song, to stay in character while no one is the wiser?