Next time, just try making up your own songs or riffs. When you go to play a tune that everyone knows, like "Smoke on the Water", you're still competing with the original, which was performed by seasoned veterans. More over, how many jams or live renditions of "Smoke on the Water" have any of us heard where everyone, especially the guitar players, knew the whole tune? More likely its just that opening riff, and you repeat repeat repeat until its flogged to death. Same thing with "Crazy Train"... everyone knows the opening riff, but it often ends there... fun to "jam" to because the opening drum and bass line is both catchy and simple to play. But once again, it usually just falls apart after that.

When you jam someone else's tune, especially when you're new and the tune is not particularly easy to play, it just ends up making everyone realize that they kind of suck. Which, is true if we're really talking about how did our jam compare to the album recorded original. This can just make things feel awkward.

Instead, just ask the drummer to lay down a beat... anything he likes. Now he's playing what he likes to play, what he KNOWS he can play, so he/she will play it well. Now its your turn to see if you can tap into what you KNOW how to play, use the technical skill you've learned so far, let your mind go, feel the music and see if you can come up with something original that works with what the drummer is playing. Sometimes it doesn't work out, but a lot of times it does, and now you are getting to know who you really are as musicians.

U2 started from very humble beginnings. Adam Clayton could barely play bass when they started, but he got swept up with group because he was their friend and they really needed a bass player (lucky bastard). They actually learned their instruments as they jammed and played together. Small wonder that they would develop a cohesive sound.

So try it yourself... its way more fun to jam with your own creative energies at the helm, without any "no, its not played like that" bouncing around in your head. And who knows, you might come up with something that is truly original and your band's journey will have begun.