Hi Margaret,
I didn't take the Musical Crawl. I did take the Dublin Literary Pub Crawl and it was excellent. You have to register in advance, they usually sell out. The tour stopped in 3 pubs (you order and pay for your own drinks) for about 30 minutes each. If no one invites you to join them, invite yourself. Folks are friendly, especially after the first drink.
I did go to the Brazen Head evening, again as a solo. Seating was at round tables of about 10 people. I chatted with the people near me at the table and they were very nice. That was the only good thing I can say about the evening. The fellow tellling the tales was boring and sometimes hard to hear. I had been to the Leprechaun Museum 3-4 days earlier. It's a guided visit and the guide was very interesting and I learned a lot about Irish culture and folklore. The Brazen Head guy told a few of the same stories, nothing more. As I left, I glanced in at one of the "regular" pub rooms (the evening was upstairs in a large private room). The music was excellent and I was so sorry I hadn't spent the evening there instead.
You can go into any pub solo any time, day or night. I went to Kilmainham Gaol and got there soaking wet, literally dripping, and they'd just sold the last tickets of the day (I think it was the last year before they began advanced sales). I was miserable but remembered I'd passed a pub a block away. I went in for a bowl of hot soup (lunch specialty in nearly every pub) and to dry out Since it was lunch time, mid-week, and off the beaten path, it was pretty empty, so after I'd eaten, drunk a pint, dried out and cheered up, I had a walk round the establishment (every pub is a warren of various rooms, usually different and usually interesting). There were a couple of retired local guys playing darts and they said I could watch. We bantered back and forth along with the bartender and a couple other patrons, I learned the rules of darts and some of the finer points, and they even let me try it (it's really hard!!). I spent a lovely couple of hours there. On another day I was in a quiet pub in Temple Bar (not so easy to find) and a single woman sat near me at the bar and started to chat. She was from Belfast and we spent a couple of hours explaining our respective country's politics and religion to each other. Wonderful afternoon. I also did my own pub crawl solo through Temple Bar. If I liked the atmosphere and the music, I'd get a pint and chat with some of the other patrons. Everyone (all tourists, mostly from the UK and Europe) was chatty.
I didn't meet a local Irish person who wasn't inclined to chat away - pub patrons, shop clerks, people in parks and museums. . . . BTW there are two theatres in Dublin, the Gate and the Abbey. I went to plays at both. London quality and less than 1/2 the price.