Severus rose when she did and offered her his hand. "It was very enjoyable, Miss Montgomery. I'll be glad to stay, I thank you."
He wasn't done with his drink, so he took her on her invitation to stay. Once again he was newly impressed with the wide range of talent the village possessed considering it's small population. Perhaps Hogwarts ought to have had a music program of some sort.
At the end of each song, he applauded with the other patrons and actually found himself staying for the whole set. When she took her next break, Severus made sure to arrange with the barkeep to buy her next drink and then met her as she was moving toward the bar.
"Well done, Miss Montgomery. I enjoyed that very much; you're quite talented. I must be going, but I hope you don't mind that I've covered your next drink."