Please don't take this in a negative way, but my experience two years ago was a bit of a let down, though I still had fun.
I lived in both Austria and Germany, and have returned to both several times. I love German food and music. My family has never shown any interest in the Biergarten so I decided to go when I was doing a solo trip.
I was seated with two other families. One was from Latin America who only spoke Spanish and were clearly confused by everything. The other was from the mid-west and mostly just ate in silence, hardly speaking to each other let alone the single stranger at the table. When the server came over to take our drink orders, I was the only one who ordered a beer. When the music began both families just up and left.
That said, I had a great time enjoying all the different dishes I'd not had in a long time, singing along with the music, etc. The servers took care of me and I chatted with several in German (they were polite to ignore my lapses in grammar and pronunciation). I ate so much I didn't have anything else to eat until breakfast the next morning!
I would go back without hesitation. Hopefully, the next time I'll have better luck with my table mates.