Left Handed Guitar Players do it different ways...

 
 
Left-handed people play guitar or electric bass in one of three ways:
1-  play a right-handed guitar right-handed,

2-  play a true left-handed instrument (or a right-handed instrument that has been altered to play left-handed, i.e. with the bass strings on top),

3-  turn a right-handed guitar upside down, pick with the left hand, and keep the strings in the same position they were, which makes them reversed from the normal order for a left-handed player. Any style of picking with the left hand is considered playing left-handed.

 
Guitarists in this category pick with their left hand and have the strings in the correct order for a left-handed player (i.e. the low string on the top). They either use true left-handed guitars or have right-handed guitars altered so the strings are correct for a left-handed player. Some of them (e.g. Paul McCartney) play both genuine left-handed instruments and right-handed instruments altered for left-handed playing.
Changing the strings on a right-handed guitar involves several things. The nut of the guitar has to be changed to accommodate the string widths. The bridge needs to be changed to make the lower strings longer than the top strings for correct intonation. On almost all acoustic guitars the bracing is non-symmetrical. On electric guitars  as much as for electric bass guitars altered this way, the controls will be backwards.

 

Some of the most Famous Left-Handed Guitar Players:

Tim Armstrong
Billy Ray Cyrus
Tony Iommi
Jo Callis - Plays guitar left-handed.
Calogero- Plays guitar and bass left-handed
Kurt Cobain
Elliot Easton
David Cook
Jimi Hendrix
George Johnson
Paul McCartney(The Beatles)
McCartney first tried playing right-handed, but was making no progress. He saw a picture of Slim Whitman playing left-handed and realized that it was necessary to reverse the guitar, pick with the left hand, and reverse the strings.
Al McKay (Earth, Wind & Fire)
Jeffrey Steele (formerly of Boy Howdy)
Cesar Rosas (Los Lobos)
Lukas Rossi- Can play the guitar with either hand.
Slim Whitman
Zacky Vengeance

 

Left-handed with strings backwards

These are players who play left-handed, but with the strings as on an unaltered right-handed guitar, thus the strings are backwards for a left-handed player. Some players in this category (e.g. Dick Dale and Albert King) had custom instruments that were basically a left-handed guitar with the strings as on a right-handed guitar, since they had learned to play that way.

Elizabeth Cotten
Dick Dale, plays a customized left-handed guitar with the strings backwards.
Coco Montoya
Otis Rush
Graham Russell (Air Supply)
Dan Seals
Bill Staines
Bobby Womack
Albert King
Bob Geldof
Doyle Bramhall II
Kris Roe (The Ataris)

 

Unclassified left-handed players

A left-handed Martin D-28. The internal and external construction is the mirror image of a right-handed guitar.

John Bigham (Fishbone)
Zeff Childress (Sanctity)
Ed Harcourt
Cheyenne Kimball
Iggy Pop
Bjarne Roupé
Gruff Rhys
Omar Rodriguez-Lopez (At the Drive-In/The Mars Volta)
Kris Roe (The Ataris)
Bent Sæther (Motorpsycho)
Andrew "Whitey" White (Kaiser Chiefs)
Lari White
Michael Zakarin (The Bravery)
Joel Stoker (The Rifles)
Aidan Horn (Last Ride In)
Fyfe Dangerfield (Guillemots)
Simon Taylor-Davis
Jill Barber
Wendy Wild
Mac Powell (Third Day)
Zacky Vengeance (Avenged Sevenfold)

 

Left Handed Bass Guitar Players

Paul Gray (Slipknot)
Paul McCartney (The Beatles/Wings/solo)
plays with strings in correct order
Jeffrey Steele
Robbie Merrill (Godsmack)
Martin Eric Ain (Celtic Frost)
Paul Wilson (Snow Patrol)
Scott Reeder (Kyuss/The Obsessed)
Doug Pinnick (King's X)
Jeff Schmidt (Bass Soloist)