Who was the Czech musician invited by Lou Reed to his 1998 White House performance?

The White House dinner (16Sep1998) honored Czech president Vaclav Havel, who had requested that Lou Reed be invited to provide music. Lou Reed, in turn, invited a Czech musician to join his group in the concert. I was seated at the table directly in front of the musicians - but I'd forgotten the guest musician's name. I would like to learn more about him and, possibly, get some of his work from Prague. Thank you, thank you, thank you......