Guest column - Stretching Time at Abbey Road by Recording The Beatles author Brian Kehew

Brian Kehew is co-author (with Kevin Ryan) of Recording The Beatles, a behind-the-scenes look at the making of the Fab Four's records. Ryan and Kehew will be presenting lectures on the long history of Abbey Road studios throughout March, a rare chance for the public to visit inside the legendary studios - see Abbeyroad.com for full details. In a guest column for Q, Kehew lifts the lid on technique develop at the north London studio: tape stretching. Plus win a trip to Abbey Road in this month's Caption Competition.

One of the hallmarks of 1960s music was the psychedelic music era, roughly running from 1965 to 1968, depending on your perspective. Whether you now consider it the coolest music ever made, or the most-dated music of all time - it certainly is a style-period that deserves some attention.

Certainly, it was one of the coolest eras of Beatles music - when they felt free to break beyond the sound of "a band" and create music that could not be done in real time. They'd already done some playing-about with sonics on earlier records; half-speed and double-speed tape recordings - like on the solo to A Hard Day's Night which is actually twice the speed they played it. These tape tricks had been done by experimental composers, and even more mainstream artists, like Les Paul... or Pinky And Perky!

At Abbey Road, these influences came to affect commercial pop music as well. So when The Beatles (and other artists at Abbey Road) began to try to replicate the distorted reality of the psychedelic explorations, they began to use the tape recorders to "stretch" the sound. When tape is speeded up or down (versus normal real-time speed) the pitch changes and the length between events changes. All this means is, the sound becomes lower and slower, or higher and faster. When done subtly, it became a powerful tool to stretch time, to bend reality without really cueing the listener that something odd was happening. In this unique time-stretching, artists found a unique effect that replicated (and sometimes induced!) bizarre distortions of perception... Listen to John Lennon's vocal here in Strawberry Fields Forever.

It has a lazy, hypnotic dragging-through-molasses feeling of altered reality. Yet to most, the clues of this were subtle; people weren't aware this was not the normal Lennon voice they were used to hearing. They did the same trick for the song Rain, where the instruments are slowed and just slightly trippy. And the opposite, hear John's voice is sped up slightly:

It has a silvery helium-infused edge to it. By speeding up the recording, time is stretched in a perceptible way, without being too bizarre. Originally, the makers of the tape machines had only been concerned with perfect linear real-time recording (mainly for classical records), so the more accurate and steady the better. Abbey Road had specially modified their tape machines to play at all sorts of unusual speeds, and this opened up a world of creative sounds for the bands of the era.

This speed-and-time stretching doesn't even cover the other cool tape tricks used for psychedelia. Those staple sounds of tape echoes and tape flanging/phasing really do define the psychedelic era to most. But the subtle speed-changing stuff was inherently effective for creating such purple hazes... and worth pointing out here, as you may not have noticed it before. Brian Kehew

For more information on the talks and visits to Abbey Road, head to Abbeyroad.com and enter Q's Caption Competition now to win a vist and a set of speakers.