The pop superstar hit the stage for her seventh night at Wembley Stadium as part of her "Eras" tour – but, at one point, Taylor's piano experienced a breakdown as she sat in front of it.

Check out the video ... Taylor called over a stagehand to fix whatever the problem was, and he partially removed the top portion of the piano to take a look inside.

He tinkered a bit with the wires before putting the lid back on as Taylor seemed more than satisfied, thanking the stagehand and letting out a high-pitched laugh.

Then she addressed the crowd and went into a little speech about the rain ... officially labeling the concert a "rain show" because the downpours lasted more than 6 minutes.

But, it didn't seem like the bad weather was much of a factor and it certainly didn't hamper the show.

Meanwhile, the packed audience loved every moment of it, including all the famous people who attended, namely Channing Tatum and Zoe Kravitz. Taylor's ex Taylor Lautner and his wife – who's also named Taylor – were enjoying all the music as well ... this comes after "Twilight" costar Robert Pattinson got a shout-out at the show.