Just curious - why not? Is there something inherent in providing services that makes it inappropriate to levy sales taxes on them? I'm sure income taxes are collected on the same services - why would sales taxes be unexpected? Is there a historical reason for it not to be common? In Canada, the GST (a VAT) is required to be charged by most service providers, unless you're selling less than $30k per year of taxable services. So yes, musicians and lawyers need to charge and remit tax for their services if they earn more than $30k/year. A bit more likely with the Lawyer than the musician.
:) Dentists and some other professions do not, List of exemptions: http://www.cra-arc.gc.ca/tx/bsnss/tpcs/gst-tps/gnrl/txbl/xmptgds-eng.html.
The rules for provincial sales tax vary in each jurisdiction of course.