Geez. This is getting out of hand, and seeing as how I need to be in bed, I'll be brief.
A marketplace is something akin to a flea market. All Chopin is doing is saying, "Hey, you vendors [Composers] out there, would you like me to make space for you to do something that earns you money?" People then take this to mean, "Hey, YC, go make me some money!" So, what's getting lost in translation here is that Chopin wants to make this place more business-friendly, add another dimension to the "market" (that currently consists of 'us', we members of YC) and attract composers who want to take their interests in music to a more professional level.
The real question, though, is whether YC is that place. When you turn part of a school/community center into a flea market, it is bound to confuse existing members. So much change over so little time has really not benefited the YC community. Do I think the idea has merit? Sure. Would I use a marketplace? Depending on the clientèle and the opportunities, possibly. Would I expect to see this become a "part" of YC? No.
I don't walk into a school looking for a flea market. YoungComposers is specific, and it makes great sense to send those within the community that are interested in becoming a vendor at a flea market to a place that is actually a flea market. It also makes great sense to send those within the community interested in buying stuff at a flea market TO a flea market, not a school. I have to say that I really like the concept, I just don't think YC is the place for it to exist. Put $10 into a domain and use your existing host and server to link up YC users to this marketplace if it ends up taking off. Otherwise, if it fails, that's just another burden on the community and on the site itself... and on you.
Baby steps lead to big things. The YC community needs all of this to slow down. We need to catch up on our numbers, return to the basics of how this site and its membership interact, we need to bring some of the old members back eventually, and we need to grow in membership. It takes time, but so did Facebook. They could have made change after change looking for ways to leverage what they had, but they waited until they were about 500,000 members strong before actually leveraging their site to make money. Nearly $19,000 went into its development over several years, then they tweaked and waited for the right time and right way to leverage their market for profit.
Think what we will about YC, it may never be a Facebook, but it has potential to be a strong contender in its more specialized market. The next proposal I think we should consider is how to reach out to music students and bring them to YC, one school at a time. Build the membership, let the community build the resources, and let time run its course. The marketplace is down the road, it's not a well-timed idea FOR YC at this junction.
That's my opinion, and maybe it wasn't so brief but w/e.