Yes. I sang in a hotel/restaurant bar area (capacity: no more than 35 people) one night in P-Town. Debra & Patrick were playing and they were wonderful: She was singing all sorts of stuff as he accompanied her on piano. From blues to jazz to modern music to country...they were excellent and she had a seriously great voice!
Sidebar: Her voice and his playing were welcome to us both, especially after the incredibly bizarre show we saw before that at Vixen. A purported comedy, at one point it featured a 'pervy Jethro Tull meets Midsummer Night's Dream meets holy puce leotard' one man act that cannot adequately be described in words. (There was also a shirtles man wearing horns and hot pink fur chaps who tap danced rather femininely...with giant fake balls dangling off his backside. That was the highlight).
Anyway, Debra and Patrick were performing a romantic Billie Holiday song when we sat down and ordered out first glass of wine. A couple glasses later, they took a break and Debra walked around to say hello to her friends in the audience. She came over to our table and not two sentences in, Jess said, "You know, Pam sings" and Debra said, "Oh yeah honey? What do you sing?" I explained that I sang the kind of stuff that she sings, especially the jazz stuff. (As you can see, I was fantastically articulate). Then she asked me what specific song would I like to sing, I said "Stormy Weather," and she said she might call me up to sing with her. With her, mind you. She was really good, and her impromptu duets so far had made her duet partner look really good. I was excited.
She went back to singing (one song was "What a Wonderful World" and she did that growly voice that sounded JUST like Louis Armstrong), and about 5 songs later, she called me up...TO SING BY MYSELF! She announched that her new friend Pam was going to come sing a solo, that she hoped I could actually sing (because she didn't know me from Adam...or Eve?...anyway...), and told me to tell Patrick my key. I didn't know my key. I guessed Ab, then added "whatever key she would do it in is probably fine." I think I lost a little credibility for Patrick at that point, but he smiled and I went back to the front where Debra was waiting with the lipstick-covered mic. She handed it to me and said, "I'll be here if you need me." Luckily, I was half way drunk so I didn't pee my pants.
I started singing and it actually came easier than I thought. I hardly looked away from Jess, my anchor in the audience for 99% of the song, and got through it. I wish I had noticed the lipstick marks on the mic sooner than in hindsight, because apparently, Debra eats the mic while she sings. That must be why you couldn't really hear me on the softer stuff, but oh well! I was loud and clear on the beginning of each verse, so I guess that was something. Plus, there were cheers and genuine claps at the end, so I think I did a good job! And it was so much fun!
For a split second when I was falling asleep that night (an hour later), I considered a career in lounge singing. Then I passed out.