Twitter is a remarkably flexible application -– an efficient news service, a way to keep up with friends, a replacement for RSS feeds, a resource for links worth sharing, a broadcast medium and two-way method of social interaction (if not quite a social network). But I’m not sold on Twitter as a music discovery engine, despite a recent proliferation of ways to push music into a Twitter feed. Simply put, Twitter and music discovery happen at two different speeds, and music discovery works better elsewhere.

Most music-tweeting services do roughly the same thing in slightly different ways: You upload a song or find it through a music search engine, the service provides a short link and/or populates the Twitter message field with a title and artist, then tells the world what you’re listening to as soon as you hit “send.” With many services, every song you’ve tweeted remains in a playlist, some of which can be integrated with the playlists of others.

The web is already full of good ways to discover music. Pandora creates personalized radio stations through an ambitious system of tagging songs based on qualitative traits. Last.fm recommends songs and artists through collaborative filtering. Imeem, MySpace Music and others allow users to create and share playlists. Blip.fm even nicks Twitter’s design in a search and playlisting service. Most of the best ones involve discovery through people, with online playlists performing the function that mixtapes and burned CD mixes did for prior generations.

By comparison, Twitter’s effectiveness as a music-sharing tool is highly limited, primarily as a matter of scale and efficiency. Many of us who have come to rely on the service face a problem of information overload, and don’t need to see something like “I’m listening to Coldplay right now!” The occasional link can be a valuable pointer, but the ongoing integration of someone’s playlist into a Twitter feed is a recipe for unfollowing. And yet, music discovery services rely on scale. No two people’s tastes match up perfectly, and it takes awhile -– or a really long playlist –- to tell whether someone else’s preferences jibe with yours. That kind of information doesn’t fit very well into a Twitter stream, because Twitter’s manic torrent of real-time information isn’t conducive to producing the context that makes music discovery work.

Still, some music-tweeting services work very well for certain purposes, if not others. Twt.fm offers a quick and easy upload-and-tweet function, but doesn’t always find the streams for which I’m searching. The exceedingly simple Song.ly searches for streams, but doesn’t allow uploads. Newly-launched Swift.fm will make an integrated playlist of songs people have shared in my own personal Twitterverse, but won’t allow me to pick and choose whose songs I want and whose I don’t. (That would be a problem for me. Everyone I follow, I follow for a reason, but musical taste probably isn’t it.)

I’m liable to tweet about a song via Imeem every now and then, but my favorite provider in this arena remains Blip.fm — a Twitter-for-music service that doesn’t need Twitter. Its resemblance to Twitter itself notwithstanding, Blip.fm is really just an instant playlisting service that gives the option of integrating other people’s songs in real time or just listening to one particular person’s playlist. Its user interface is so instantly gratifying that I don’t mind the iffy search results, and its YouTube integration offers a nifty video option. But at the rate I use it -– sometimes 15 songs in an afternoon, sometimes not at all for a week -– I’d never push its feed into my Twitstream. Which makes it a perfect example of something that works better outside of Twitter than in it.

What do you think? How important is it to have music streams integrated into your Twitter feed via these services? Is an oversharer of music a candidate for unfollowing, and how much is too much? Or would you rather use music discovery services on their own?

This article also appeared on BusinessWeek.com.