Take a look at the three first tag pages, there are two things to notice:
There are tags that obviously get more attention than the majority of tags, for example piano.
There are tags that barely get attention, and tags that are just missing.
trumpet and choir only have two questions, there are no questions about the clarinet.
I gave instruments as an example, but you could notice the same for other topics that aren't instruments.
We currently have 276 visits/day
as noted on our Area 51 proposal.
1,500 visits per day is good, 500 visits per day is worrying. A great site benefits people outside the community. Eventually, 90% of a site's traffic should come from search engines.
Note the last sentence, other communities work great because a lot of people just find the questions.
So, if we want this site to survive we need to cover more topics more in-depth.
By having more topics covered that fit under our scope we will draw attention from more than just pianists and singers, and by adding more depth in tags that barely have questions we provide enough information for new visitors so that they have reason to stay.
As outlined by Matthew our questions have influence on our sites future, so they should be good:
Meta - We should try to produce more "expert" questions
Yes, it's important that we don't ask questions to have questions, make sure they have quality.
Blog - How should we ask our first questions
This again applies to the producing more "expert questions", and further more, if we cover more topics more in-depth now we will have a community that has more in-depth topics.
To summarize this whole idea:
Our site is about "musical practice & performance" and meant for "musicians", we should makes sure that for example "trumpet players" see good value in our site...
...and more important: that they can find our site.