The album art can be displayed in alphabetical order by artist or by album name. Lets say your album art is displayed by artist.......
Those two sliders are a way to "jump" to certain artist albums in your loaded library. The slider on the left allows you to select the first character to jump to. Lets say you set that slider to "M", then this means to "jump" to all the artists starting with "M". Now, if you have 200 artists starting with "M", then jumping to the beginning of the "M" list is nice but not really that nice since you would still need to flip multiple pages to get to the middle of the "M" artists. So if you wanted to get to "Motley Crue" albums you would need to flip multiple pages to get to the artists starting with "MO". As a result, the second slider (the one of the right) allows you to select a second artist character to "jump" to. So if you set the second slider to be "O", then you will "jump" to all artists starting with the two characters "MO".
Example .....lets say you have the following artists:
Maroon 5
Marvin Gaye
Marvin Hamlisch
Mary Chapin Carpenter
Mary Jane Girls
Mary Wells
Matchbox 20
Mathew Wilder
Mavericks, The
Maxi Priest
Maxine Nightingale
MC. Hammer
McCoys
Meat Loaf
Men At Work
Men Without Hats
Meredith Brooks
Merle Haggard
Merrilee Rush
Metallica
Michael Bolton
Michael Buble
Michael Damian
Michael Jackson
Michael Johnson
Michael Martin Murphy
Michael McDonald
Michael Sembello
Michelle Branch
Mick Jagger
Midnight Oil
Mike and The Mechanics
Mike Pender
Mike Post
Milli Vanilli
Mindy Smith
Minnie Riperton
Miracles, The
Motley Crue
Motorhead
Mr Mister
Mr. Big
Mtume
Mungo Jerry
Murray Head
Music Explosion
Musical Youth
If you set the left slider to "M" then the album art displayed will start with all the albums for your first "M" artist .... which is "Maroon 5" albums. Now, lets say you really were trying to get to the "Motorhead" albums and do not really want to start paging through the album art until you get to the artists which start with "MO". You can instead set the second slider (the one on the right) to be "O", meaning your "seek" characters are now "MO". This will jump you to all the albums from the artists starting with "MO". This will result in all the albums from artists starting with "MO" being displayed. Basically, you should see "Motley Crue" albums and "Motorhead" albums being displayed.
Hope this made sense.
In a nutshell ..... the slider on the left sets the "first seek character" and the slider on the right sets the "second seek character". They allow you to jump to certain sections of your loaded library to help minimize the number of page flipping which must occur to get to a certain section of your library.