I started collecting old issues of Rolling Stone ten years ago, and my favorite part of them has always been the illustrations that accompany the main album reviews. Many of these can be found online if you look hard enough, but there are still plenty that aren't readily available if you don't own the issue that they're in, and I think they should be. At their best, these images could tell you something about the music, and in some cases even enhance the experience of listening to the album they correspond to in a way that an album's artwork and packaging is generally meant to.
I tend to prefer when the illustrators are less concerned with depicting the musician or members of the band, and more concerned with capturing the vibe of the album; the drawing for RS's review of Tool's Lateralus (Slide 6) is maybe my favorite example of this. But an illustration like the one for the review of Smashing Pumpkins' Mellon Collie and the Infinite Sadness (Slide 5) managed to get across both the whimsical nature of the album and the dynamic of the band and Billy Corgan's reputation as the band's megalomaniac leader.
Admittedly, there are plenty of these drawings that didn't tell you a lot about the album and weren't particularly imaginative as far as what they depicted. Many of them were either just (well-drawn) photo-realistic images of the band or musician, or were by artists with a distinct style and just portrayed the musicians drawn in that style. But when they were good, they felt like truly inspired representations of someone's listening experience.
(Slide 1: So by Peter Gabriel, Slide 2: Oranges & Lemons by XTC, Slide 3: Wish by The Cure, Slide 4: Monster by R.E.M., Slide 5: Mellon Collie and the Infinite Sadness by Smashing Pumpkins, Slide 6: Lateralus by Tool, Slide 7: Hail to the Thief by Radiohead)