1. Direct linking using an LCCN.
Here is the link for Van Morrison: http://worldcat.org/identities/lccn-n85-148183.
See Thom's post for the detail.
The name finder service gives back a list of candidate names with URI's, ranking information, a sample title and other information about the name. .... NameFinder looks at lots of possible variations in names, so almost always results in a list rather than a unique Identity record. [Outgoing: Linking to WorldCat Identities]
Here is Van again: http://worldcat.org/identities/find?fullName=Van+Morrison. Or http://worldcat.org/identities/find?fullName=george+ivan+morrison. (There is also a SOAP version.)
4. SRU searching
There is also full SRU searching and again Thom provides the detail.
Finally, here is a list of his CDs in Worldcat.