Tony wrote about his friendship and collaboration with Lady Gaga in his book Just Getting Started.

We began our musical association by recording “The Lady Is a Tramp,” the great Rodgers and Hart song we both love, at Avatar Studios in New York City. One of the first things you see about Gaga when you work together in the studio is her utter professionalism and thoughtfulness. She doesn’t just sweep in, like some other stars, oblivious to others. She stops to shake hands and talk to the engineers, the musicians, the office personnel, and the people who run out for bagels and coffee. She is that rare, huge talent who knows that you need to nurture and encourage collaboration to become a truly big star.

Gaga and I got better together as we went along. But from the first, there were sparks, banter, and a kind of effortless back-and-forth that inspired improvisation. It was fun, and it was electric.

There is no mistaking the fact that the collaboration I’ve enjoyed with Lady Gaga has made me and the music to which I’ve devoted my artistic life appreciated by a whole new generation. They have kept me going past the age of ninety. And they have kept the music going on and on and on, into new generations.

We were being interviewed once, and I heard Gaga say that one of the things she’s learned from our partnership is that “You don’t have to fear growing older. In my generation, this is like at the center of everything, especially in celebrity culture: it’s all about staying young and staying perfect and staying youthful. . . . But Tony has remained the same, and there’s nothing hipper. There’s nothing hipper than being talented at something that you love, in having passion, and that is classic, and that is timeless.” Did you catch that? I think Lady Gaga called me hip.

Just Getting Started is available at Amazon, Barnes & Noble, and other booksellers.