I watch it on the Frick Museum site. I forget how I first learned about it but have been watching it since last summer, almost a year.
One can tune in on the hour, 5pm Fridays and watch it live or catch it later. When you watch it live, you get to make comments as the show unfolds. Mostly people saying Hi. I try to comment on the substance of what is being presented.
After I signed up I get an e-mail from the Frick every Friday with a link to tune in.
I even donated $100 last summer since I was enjoying the shows. I studied some art history at university so can relate to the approach they use, which is like an mini art class each session.