well, if your plan is to cut out the middle man (aka Agent or publicist)

You would have to find out the next event or party this particular artis will attend, or where they frequent!

Fat chance of getting "major" stars to talk to you directly unless you know someone who knows someone....

Normally all bookings for ARtists major or otherwise lucratively famous somehow you have to go through their staff.  This includes bodyguards

and pooches!  some pooches are ankle biters if they think you're after their owners' money!