In ancient times (like the 1970s), musicians would take a vinyl LP record and manually spin the record on a turntable, slowing it down to be able to better hear and understand the performances, like guitar solos and complex chord changes. With the CD-GT1 mkII, you get a training method that's even better. Not only can you slow down the speed of the CD by up to 50%, but you can do it without changing the pitch of the original material! After you learn the lick at a slow speed, you can increase the tempo in steps until you can match the original performance note for note. Also, you can change the pitch of the CD without changing the speed... use this feature to "tune the CD" to your guitar.