With the beginning of the year 1900 Pablo Picasso is very dependant with the Spanish painter Carlos Casagemas whom it met in Barcelona. They divide a time the same workshop. Casagemas finances even their first voyage to Paris. After their installation, whereas Picasso adores the environment of the expensive Montmartre hillock in Toulouse Lautrec, Casamegas falls in love with a dancer from the Moulin-Rouge, Germaine. This adventure turns badly and dark Casamegas in depresses and alcohol. The February 17th, 1901 Casamegas goes back to Paris while Picasso is in Madrid, tries to kill Germaine then commits suicide of a ball in the temple. Pablo Picasso is terribly affected by these events, it paints his friend in his coffin but this emotional trauma marks the beginning of its blue period. (1901-1904). Of course blue is the dominant color of works and the topics are dark : death, old age, poverty, alcoholism, the infirmity, prostitution. The faces and the bodies are deformed and stretched with the way mannerist of Greco that Picasso studied. The Old Guitarist reflects the states of hearts of an artist marked by the dramatic loss of his friend.