Making a Greatest Hits compilation is a lot like making a mix tape: unless you make it yourself, it’s going to be missing that one obscure song that has been stuck in your head for days and would make the whole effort worthwhile. Raise your hands if you’ve popped a Best Of in the CD player and thought, “Yeah it’s good, but damn it, why isn’t my favorite song on here?”

Yep, Greatest Hits are a tricky business for everyone, let alone the seminal Pink Floyd. Just drop their name in a conversation and hear people sing “All in all you’re just another brick in the wall” in their best British schoolboy accent or hear about the time they tried to simultaneously play Dark Side of the Moon and “The Wizard of Oz” but regrettably were too high to sync it up correctly.

For better or for worse, Echoes: the Best of Pink Floyd whittles the band’s expansive, four-decade career into 26 tracks. The two-disc set does a surprisingly good job of diversifying the selection. While Dark Side of the Moon and The Wall may have launched the group into superstardom, some of their most intriguing work is from earlier albums. Staples of classic rock radio, like “Money” and “Comfortably Numb,” do have their moment in digitally remastered glory, but Echoes wouldn’t be much of an album without cuts from Meddle or The Piper at the Gates of Dawn. The latter features Syd Barrett, the group’s original front man, and provides an interesting look at what Pink Floyd would have been had he not gone insane from an overdose of LSD. The early single “See Emily Play” is psychedelia at its best: catchy, trippy and completely stuck in 1967.

With Barrett’s disappearance, the band struggled to develop its sound, straying from the short sci-fi pop on Piper to intertwine long, complex musical passages with inspired rock ‘n’ roll. Echoes off Meddle provides the archetype for Pink Floyd’s later and better known works. [huh?] Enormous in scope and length, the song shuffles through jazz, funk, prog and sheer avant-garde noise, yet never loses its focus. David Gilmour’s and Richard Wright’s dreamy vocals and intricate guitar work make this track vintage Floyd.

But of course Echoes has its share of glaring mistakes and omissions. Where are “Young Lust” and “Have a Cigar”? Why isn’t there anything from 1970’s wonderfully experimental Atom Heart Mother? Why even bother with songs from The Division Bell?

Granted, these complaints are more a result of wanting to make my own “Best Of” mix than any error by the compilers. Generally, the songs work well together, a surprise since they are mainly culled from Concept albums, with a capital C. The one glaring exception is the first track on disc two: “Shine On You Crazy Diamond.” While this is arguably one of Pink Floyd’s best, it’s also one of the longest. For its original release on Wish You Were Here, “Shine” is split into two parts that bookend the album; here, presented as one long piece, it’s too much of a good thing.

While Echoes serves as a great introduction to Pink Floyd, it’s nothing the initiated can’t live without. Its length provides an inclusive tour of the band’s career, but then again, two and a half hours of even the most indispensable group can prove trying at times.