Gaga has long expressed her admiration for Madonna, calling the pop icon an inspiration. Comparisons between the two divas have been inevitable, from their dance-hall beats to their risque musical treatment of sex and religion. The two even teamed up for a "catfight" skit on "Saturday Night Live" in 2010.
But last February's release of "Born This Way" had many questioning whether the Mama Monster had gone too far in emulating her idol. The song, critics charged, was stunningly similar to Madonna's 1989 chart-topper, "Express Yourself."
Gaga would go on to say that she got an e-mail from Madonna's "people" saying they supported the song, but a representative for Madonna later said she was unaware of any such e-mail.
When ABC News asked viewers to contribute questions for Cynthia McFadden's interview with Madonna, the most popular request by far was that McFadden find out how the singer feels about Gaga.
McFadden did, starting with the question of whether Madonna felt Gaga was "copying" her. The pop singer's response, at first, was complimentary. She called Gaga "a very talented artist" and said she admired her songwriting. But she owned up to the connection between Gaga's music and her own.
"I certainly think she references me a lot in her work. And sometimes I think it's amusing and flattering and well done," she said.
Madonna said sometimes Gaga's work also appears to be a "statement about taking something that was in the Zeitgeist, you know, 20 years ago and turning it inside out and reinterpreting it."
"There's a lot of ways to look at it. I can't really be annoyed by it …because, obviously, I've influenced her."
But the Material Girl became coy when the conversation turned to "Born This Way."
"When I heard it on the radio …I said that sounds very familiar," Madonna said.
Asked if that felt annoying, Madonna responded, "It felt reductive."
Pressed as to whether that was a good or bad thing, Madonna told Cynthia McFadden to "look it up" - we did; the term means "minimal" or "crude" - before smiling slyly and taking a sip from her tea cup.
See more about what Madonna had to say on Gaga, including whether she'd do a duet, tonight on "20/20? at 10 p.m. ET.