"at a lesson" is a correct and usable phrase in written English.
You can use it when referring to a specific teaching session, such as "We learned a lot at the lesson last week."
Young Toby never cried at a lesson again.
"Almost 30 years ago," he said, "one of my students, Anthony Martin, arrived at a lesson with a Baroque bow, which I had never touched before, and I asked him if I could use it for a couple of days.
I never sounded as good at a lesson as I did when I played alone.
Piano is particularly helpful, as you can learn your music at home and not have to be taught note-by-note at a lesson.
Even if you were a pro at a lesson 2 months back, you may prove to be a dud in exam, thanks to forgetfulness.
While this may seem harsh, an instructor could face serious legal and financial trouble if a student is injured or even dies at a lesson.
I'm one for church and prayer and I look at it as a lesson learned.
She had been teaching cooking classes herself at $4 a lesson.
At $60 a lesson, it had to have some degree of seriousness, but do I want to meet the type of adults who take mermaids that seriously?
At $60 a lesson, it had to have some degree of seriousness, but did I want to meet the type of adults who take mermaids that seriously?
Both "George Lopez and Bernie Macac" rely too much on old, learn-a-lesson-at-the-end conventions.
