I looked at the criteria on the "Area 51" listing and it seems that Musical Practice & Performance has exceeded every one of the criteria to get out of "beta" stage with the exception of only one: we don't average many new questions per day. But this site has been "beta" for more than two years.
I know nothing about the inner workings of StackExchange; perhaps one of the company employees could enlighten me about this.
That Questions per Day number is a problem, and while we are not allowed to go into detail on the analytical data, this seems to be down to not getting enough new users in.
Our total page views and number of visits are increasing and the curve trend is upwards, which is excellent, but our new user graph is pretty flat. I think we'll have trouble hitting the threshold until this picks up - simply to be able to get enough questions per day. The upside is we are growing, slowly, and as the SE devs remind us we can stay in beta for an extended period, as long as it looks like we can keep growing. Interestingly, we are getting lots of new visits - so one problem seems to be the conversion ratio.
In trying to remember similar points in Sec.SE's history, we did a strong piece of publicity work (actually a few) identifying hot topics in security in the news or on the internet and making sure we had posts about them linked from blogs etc. thus ensuring we built credibility on a lot of sites.
Music.SE is going to be a different beast, but we could do something like have some questions related to Eurovision (yes, I know...but it has a large audience, so piggybacking off the #eurovision hashtag would be not necessarily bad) or SXSW or around popular music (I am a bit of a fogey here, with most of my favourite bands dating from the 60s and 70s so pop music isn't really my forte, but if a popular artist has some special technique or style that could make a good topic)
Active voting is also essential - not only to help encourage good questions and answers, but also to enable a higher number of 10k members of the community.
As a reward for voting, we have the shiny Electorate badge - which only two people have so far (@MatthewRead and @luserdroog) earned here! We don't seem to get many highly voted posts on Music.SE. Perhaps our regulars should revisit older questions and check for posts which deserve upvotes, or ones which could do with better answers.
Update 30 Aug 2013 Did some more thinking on number of visits. As I moderate two other sites, I can do a read across of how we stack up, and I have a couple of points to note, without giving away too much of the in depth statistics:
On Security, by end of private beta we already had more visits per week than Music has. In remembering back to those times, the core things the entire community did was to tell their friends, encourage posts on bulletin boards and forums and generally encourage people to come and check it out. A large number of those people in security also use computers as part of their day job - so it is easy to get them involved here. A large number are active across the Stack Exchange network.
On Music we have a small core of active users, almost all of whom are active elsewhere on Stack Exchange, and then a much larger number of occasional visitors who have no other SE accounts. These feel to me like non-IT folks, so our challenge here is how we make this site as welcoming as possible to them.
I think our scope is correct (despite the occasional post suggesting we allow 'who is this singer' type questions) - but can we target music schools or music theory and practice courses at colleges and universities, maybe?
Also, everyone follow the StackMusic twitter account and retweet good tweets!
What Dr. Mayhem said is mostly right. Music.SE is doing just fine. It is a healthy site that has great numbers in nearly all beta categories.
That said, the private beta isn't a "hit the target number" game. We don't want to graduate a site just because it got the right numbers and, conversely, won't hold a site in beta just because it didn't perform in a certain metric.
What we look for are signs that the community is growing and can sustain that growth after graduating. Graduated sites work under a different, stricter, set of rules, so we need a diverse (reputation wise) user base that can remain active after the switch, voting, flagging and editing to ensure the quality remains great.
Music.SE is doing very well, but it needs new users to come and stay, to remain active and grow with the site. Right now the best thing you can do to help the community is to bring more people in. Tell your friends, your band, your students, your family. Show them this is a great place to get your questions answered on a lot of topics.
As Dr. Mayhem also said, piggybacking current trends is a good strategy as long as it doesn't pull the overall quality down. Use events like the NAMM Show, SXSW, Eurovision, or whatever, that you know will generate a lot of interest online and make the site relevant to that subject. As long as the content is great, there's no harm in playing for popularity.
So don't worry that the site is still in beta. It isn't a race.
Keep posting, keep voting and tell more people to come join the fun!
Lately, I have been coming to the conclusion that the moderation is too strict here. Though many would disagree, I am also active in TeX-SX which is relatively a bigger one compared to here and there is a familiar pattern from the early days that there is no flexibility on the rules. I agree that without moderation it would be a disaster but too much of it is equally hurtful.
Every potential nice/fun question is closed with downvotes which is scaring new users away and making the site very dull (my personal opinion). With dullness, I mean only chord progression, instrument maintenance and a few other recurring themes.
As an example, we have almost unanimously dropped the use of downvotes in TeX-SX. It doesn't serve any purpose outside SO and there things are ridiculously hostile. And we have the highest voting users over the whole network. Rep points are useless and we use it as mark as read to be honest (at least that's what I'm doing).
I don't understand how something like music is so boring when it comes to Music-SX. I know everyone is dying to tell me about the difference between a forum and a Q&A but I emphasize I am familiar with the format (check my profile if really an evidence is needed). A discussion does not need to be a post under post, it can be different answers covering different aspects of the topic plus we can use the community-wiki option extensively instead of downvoting and closing questions. Otherwise this SX is destined to stay like a lonely 5-star intercity hotel.
I don't think I have to repeat that these are my personal thoughts, that doesn't have to be correct or accurate.
