P Perf Performing News Today

Gets underway in about one hour held at the american museum of natural history in new york where we find cnns bren with a preview. bren, who have you caught up with so far? >> reporter: listen, pam, we have amazing celebrities with us. i want to talk to them now. we have the legendary diane warren and sofia carson with us and they are performing tonight, which is -- >> you wrote it. >> shes the one doing the p perf performing. im the one not trying to mess up on the piano. [ laughter ] >> report...