You can use Regex(), but you might also find it easier to use ListItem():
Artist:
=ListItem([Artist-Name], 0, / |/ )
Name:
=ListItem([Artist-Name], 1, / |/ )
The first is used to assign Artist, the second to assign to Name.
Using Regex(), which is wrapped by an If(), you can safely use it against even an Artist-Name without a " | " separator:
Artist:
=if(regex([Artist-Name], /#(.*) \| (.*)#/), [R1], [Artist-Name])
Name:
=if(regex([Artist-Name], /#(.*) \| (.*)#/), [R2], [Artist-Name])