Changed Music Forever
The Beatles 1967 album Sgt. Pepper's Lonely Hearts Club Band changed the world of "pop" music when it was released. It made people realize that popular music could be more than just something to tap your toes to. It could be "art." It could be a thinking man's music.

The Focus Was On The Mono Mix
One thing that you don't hear much about when people discuss Sgt. Pepper is that when The Beatles were recording and mixing this legendary album (along with their producer George Martin and their engineer Geoff Emerick) their focus was mostly on the mono mix, not on the stereo mix that most of us have been listening to on CD.

Mono Was The Standard
Why were The Beatles focused on mono? Because that was the "standard" at the time. It's just how most people listened to their music in 1967. Stereo was still a relatively new thing. And while they did do a stereo mix for Sgt. Pepper not nearly as much time and effort was spent on getting it right as with the mono mix. In fact, the band was very involved with the process of the mono mix but mostly uninterested in the stereo mix.

As It Was Meant To Be Heard
Because of the focus on the mono mix there are some Beatles fans who feel that the mono mix of Sgt. Pepper is the "real" version of the album as it was really meant to be heard. Many have said that the mono mix is actually far superior to the stereo mix that most of us now know. Included among those who have said the mono mix is better is John Lennon himself.

Only The Stereo Version Was Put On CD
When The Beatles music was released on CD in the 1980s only the stereo version of Sgt. Pepper (and their other albums) were released. Up until now there's been no easy way for Beatles fans to hear the mono Pepper. You would have to find an old original mono Sgt. Pepper vinyl LP (which could be hard to find and expensive once found) and of course you'd have to have a record player! 

Sgt. Pepper Released In Mono On CD On 9/9/9
Sgt. Pepper and the rest of The Beatles albums will finally be released in their original mono on CD on September 9, 2009 as part of a box set. On that same date remastered versions of their stereo albums are being released as well as The Beatles Rock Band video game.