Cameroon midfielder Alex Song completed his £15million move to Barcelona on Monday and said former Arsenal team-mate Cesc Fabregas will help him settle at the Nou Camp.
Song signed a five-year contract with the Catalan giants, bringing to an end his time with the Gunners.
The Cameroon midfielder posed for the traditional photo in front of the club's insignia before passing a medical examination and meeting with Barcelona President Sandro Rosell.
He later posed in the club's famous blue and red kit before the Joan Gamper Trophy match against Sampdoria in the Catalan capital.
And Song was delighted to complete his move, telling Barca TV: 'Today is a very good day for me and my family. Very happy to be here, this is the best team in the world, playing at a club like Barca is something I wanted when I was young.
'I know Cesc very well, I slept at his house last night,' he said. 'He's a very good friend of mine, he will help me to integrate.'
The defensive midfielder added: 'I always wanted to play for Barca, with Cesc Fabregas, (Lionel) Messi and (Andres) Iniesta. It is a great day for me.'
Song has been brought in to replace Seydou Keita, who played a limited, but important role in providing Barcelona with a more physical presence in midfield.
Yet the Cameroonian is keen to make the holding midfield role his own at the club.
Barca doctor Ricard Pruna said after Song's medical: 'He has a very low body fat percentage and very good muscle quality. All the tests have come out satisfactorily and he is available to the coach.'
A statement from Arsenal read: 'The transfer of Alex Song to Barcelona has been completed for an undisclosed fee. Everyone at Arsenal would like to thank Alex for his contribution to the club and wish him the best of luck for the future.'
Song is Barcelona's second signing this summer after defender Jordi Alba, who joined from Valencia.
On Thursday, Barcelona will host Real Madrid in the first Classico of the season and first leg of the Spanish Supercup.