The Queen of Soul is extending her online kingdown. Aretha Franklin joined Twitter earlier this month, though she's only tweeted seven times since. Still, we're curious to see what the elusive legend has to say for herself. And maybe Aretha can convince these other music stars to join the Twitterverse as well. Some are reclusive and mysterious, others are entertainingly off-the-wall; either way, we're sure these icons would be the highlight of your Twitter timeline.