A segment of rockdom wailed and gnashed its teeth when the Eagles returned to the road without the late Glenn Frey. But the sad truth is, nobody ever really reunites.

From Guns N' Roses and Journey to the Rolling Stones and Van Halen, there are scarcely any bands touring with all of their original members. What about U2, you say? They don't count because they've never broken up and never replaced a band member.

More typical is a band like Styx, who are missing somebody, or the Electric Light Orchestra – who are missing almost everybody. The classic-era lineup of Fleetwood Mac tried to get back together in the late '90s, but inevitably ended up working without Christine McVie, then Stevie Nicks and then Lindsey Buckingham over the years.

You wouldn't know it from all the complaining fans do, but this, in actuality, is the norm. Members grow tired of the road, or – quite simply – tired of one another. Some version of the old lineup gets back together, but without that one guy who used to drive them nuts. Or the one member who died. They do a one-off show, but can't keep it together on the road – much less record new music. Fans are left, over and over, to wonder what might have been.

This doesn't just impact the old-guard classic rock bands, either. Newer acts like the Replacements and Smashing Pumpkins have staged partial reunions too. As you'll see in the following list, nobody ever really reunites.