Well for your use case of distributing your own music, Bitmagnet wouldn't be necessary.
What a DHT crawler like Bitmagnet does is the following:
1. Take a few initial "bootstrap" torrents and ping them to see which IP addresses are seeding that file
2. Ping those IP addresses and ask what other files/torrents they're seeding
3. Ping those torrents to see which IP addresses are seeding that torrent
Rinse repeat.
So to distribute your music to fans, you'd just want to put magnet links to your music on your site.
That's not correct. Torrent swarms and the DHT are separate. Each torrent basically forms its own small network of TCP connections to exchange data specific to that one torrent. While the DHT is a network shared by all clients that speak the protocol and it's carried over short-lived UDP query-response exchanges.
You have to be participating in a torrent swarm in order to bootstrap yourself into DHT at all. Bittorrent's DHT is not a network independent of torrent swarms. You need the address of a peer who is already part of the network in order to join it, and you have to get a list those addresses from somewhere.
Which of these methods is not obtaining the address of a node in a swarm, or hitting a tracker for a list of nodes in a swarm?
> People have used the DHT for non-torrent-related purposes.
This is simply non-responsive. People have used a DHT overlaid on the collection of torrent swarms for non-torrent related purposes.
> And nothing dictates that that has to be obtained via the bittorrent peer protocol.
This is a silly distinction. You also don't need to join a swarm to get on the DHT if I join a swarm to get on the DHT, write down the addresses I get on a piece of paper, then email you those addresses, which you plug into your handwritten specialized client that only knows how to join the DHT.
You don't need to ping anyone to crawl the DHT. You can passively wait and you'll get DHT queries in the form of "I'm looking for people seeding XYZ. Do you have a list?". You can just save those somewhere and you'll accumulate a list of active and new torrents.
Writing a DHT crawler is super fun, I suggest everyone to get a cheap VM and write/run one.
What a DHT crawler like Bitmagnet does is the following:
1. Take a few initial "bootstrap" torrents and ping them to see which IP addresses are seeding that file 2. Ping those IP addresses and ask what other files/torrents they're seeding 3. Ping those torrents to see which IP addresses are seeding that torrent
Rinse repeat.
So to distribute your music to fans, you'd just want to put magnet links to your music on your site.