Yeah, it sure can! A lot of great blues instrumentals only have a drum beat and a bass line... the rest is lead guitar. I think that sound the best personally. One of my favorite backing tracks to jam to is the one from Tin Pan Alley by Stevie Ray Vaughan its just a slow bass line and a slow drum beat. But sure, you can start out with a scale in whatever key you like... obviously you might want to choose a blues pentatonic scale to start with... and just play away try to express yourself and make the guitar talk... thats how I usually go about it.