The Writers’ Guild of Canada (the screenwriters) had a first response here the day the bill was made public.
This was Access Copyright’s preliminary response.
The Songwriters Association of Canada response is here
The American Federation of Musicians has a response here
Writers’ Union of Canada analysis of C-61 is here.
SOCAN: preliminary response is here.
And here is CARFAC Ontario’s response.
A lot of CCC member orgs are still doing their due diligence on this thing. More links as they come in.