Today is a sad one for fans of classic rock, progressive rock, and the bass guitar in general: Chris Squire was one of the most deft and appreciated players of four string to emerge from the first generation of prog rock bands, and played in every one of Yes's concerts for more than 45 years. He'll miss his first show with the band on August 7 when Yes opens a tour with Toto: Unfortunately, Squire succumbed to leukemia this weekend, shortly after he had announced his first hiatus from group. Yes has long shuffled members but Squire would end up being the one constant, and now the group will have to look deep at itself before it continues touring post-2015. For just a brief overview of Squire's best bass parts, check out the five tracks below from bios massive discography.

In order from (relatively) least excellent to most excellent:

05) "The Fish (Schindleria Praematurus)" (1971)

The biggest complaint that institutions such as the Rock and Roll Hall of Fame make about prog icons such as Rush, King Crimson and Yes is that their instrumental virtuosity gets in the way of the music's effectiveness. Although your correspondent would disagree on the whole, we'll also admit that this is sometimes true. Yes's breakout album, Fragile, occasionally featured an attitude that served to showcase individual talents versus a larger whole. This made itself evident in a series of songs that demonstrated the talents of each of the individual members, respectively. Although perhaps not a part of the greater good, it's great to hear musicians such as guitarist Steve Howe show just what they can do. Squire got his moment in the brief "The Fish (Schindleria Praematurus)." We prefer his bass as an integral portion of the band's hits, but doesn't mean we don't get a kick out of hearing him go it alone for a few minutes.

04) "Silently Falling" (1975)

When Squire announced his hiatus from Yes a few months ago, he noted that Billy Sherwood would be filling his shoes for the scheduled tour dates. It made sense to some degree—Sherwood was a member of Yes from 1997-'00—but it also confused some...Sherwood is primarily a guitarist. Most aren't surprised to know that when you're that good of a musician, picking up on other instruments isn't challenging. Indeed, Squire himself dabbled on a whole slew of instruments throughout the history of Yes, and his secondary talents came in particularly handy when he released his sole solo album Fish Out of Water (yes...he really dug the "Fish" theme). The best track on that album, "Silently Falling," features a typically excellent bassline from the headliner, as well as vocals and a 12-string guitar contribution.

03) "Heart of The Sunrise" (1971)

Spoiler alert: Despite releasing 21 albums as a member of Yes, three of the five songs featured in this list come from one album, 1971's Fragile. We feel kind of bad about that...but we would posit that this was in fact the band's most seminal album, and that Squire's contributions to it are almost enough to constitute a career's worth of work for many dime-a-dozen players. So...sorry we're not sorry? "Heart of The Sunrise" was the closing track on the album, ensuring that Squire would go out on a performance (nearly) as epic as the one he gave to open the album (more on that later). As was the case with many a Yes song, the tone was set early by Squire's bass riffing, and the introduction here features a progressive riff that jumps between 3/4 and 6/8, pausing only for a more poppy funk interjection before launching into the body of the song.

02) "The Gates of Delirium" (1974)

Perhaps the most distasteful part of progressive rock for casual listeners is its bands' willingness to tackle epically long songs. Such was the case when Yes opened its 1974 album, Relayer, with the 22-minute "The Gates of Delirium," almost a concept EP (taking up the entire A-side of the album) within a concept album telling of the horrors of war. Those familiar only with Yes's more popular songs may be more familiar with the track "Soon," which was released as a single from the album and consists of the last four minutes or so of the greater song. If you haven't heard the first 16 minutes however, you haven't gotten the whole experience. A 20-minute-plus song has the potential to be hell for a bass player—lines repeated to death—but not Squire. He shifts fluidly throughout the entirety of the track, offering an overall piece of work that could almost function as a standalone listen.

01) "Roundabout" (1971)

What else would we choose for the best bassline in Squire's career? OK...we're willing to bet that there are hundreds of Yes fans and bass fanatics that would point to individual riffs as being more complicated or packing more flair. We're not going to disagree with them, but if you have to choose one song that demonstrates the influence and role of Squire within his band, you'd have to choose "Roundabout." We already alluded to how Fragile is (again, in our opinion) the breakout record for Yes as well as it's best effort overall. This single opened the album and immediately clarified for listeners how essential Squire's playing was. The guitar has always been considered a lead instrument, with the bass serving as the "rhythm guitar" of sorts, but the formula is almost flipped for "Roundabout," as Squire chugs along and Howe does his best to keep up. It's a formula that Squire employed time and time again with Yes: Technically serving as the rhythm section but simultaneously pulling at the strings of the band's complete sound.