Rap has been taking itself too seriously for decades now, and when it does the results can be ridiculous, and even giggle-inducing. They can also be glorious. Sole takes himself more seriously than most, and while there's nothing on Nuclear Winter, Vol. 1 (the first in a projected series of mixtapes) that will make you laugh out loud, there are plenty of moments that will make any independent-thinking listener roll his or her eyes and maybe snort a bit, as well as a good number of tracks that are original and insightful both musically and lyrically. Sometimes those moments follow on each other directly: on "My President," Jared Paul (of Prayers for Atheists) snidely refers to Barack Obama as a "black Republican" (cue the eye-rolling), but eventually it becomes clear that his real beef is with the loss of the public option from the President's health care legislation -- which is, you have to admit, a pretty novel topic for a hip-hop track. Elsewhere you get oblique references to Thomas Hobbes, a takedown of public-relations pioneer Edward Bernays, and an unusually deliberate and even thoughtful rumination by Ceschi Ramos on implications of modern technology. Back on the eye-rolling front, J-Swagg opines that "it's hard to look pretty when you're marching on the Pentagon" (please: is there anything more photogenic than a march on the Pentagon?), but near the end of the program Astronautalis brings a bracingly old-school flavor to "Juicy," realizing a perfect balance between urgency and restraint in his flow. There are much worse things in pop music than self-seriousness, and Sole and his collaborators are to be commended for pushing the envelope a bit.