The Cameroonian midfielder signed a five-year deal with the Blaugrana on Monday to complete his €19 million move, and Song has revealed the transfer is a dream come true for him.
"I am very happy to be here. This is the best team in the world, playing at a club like Barcelona is something I always wanted when I was young," Song stated in an interview with Barca TV.
"I hope the team will continue to win. This is a winning team. They win everything. I will give my best in training and when I get the chance to play I will do it."
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"I know Cesc very well, I slept at his house [on Sunday]. He's a very good friend of mine, he will help me integrate."
Song could make his official Barcelona debut on Thursday when they play Real Madrid in the first leg of the Supercopa Espana, a fixture he is relishing the prospect of featuring in if called upon.
"If the coach wants me to play, I'm ready for that," he claimed. "It would be great to play the Supercopa against Madrid."
Song has been regarded as a direct replacement for Yaya Toure, who left Barca for Manchester City in 2010, and competition for current first-choice defensive midfielder Sergio Busquets.
However, the Cameroon international insists the sole purpose of his arrival is to help the side rather than stir up rivalries with team-mates.
"[Toure and I] are different players, we each have our own skills," he affirmed at his official unveiling.
"I didn't come here to take Busquets' place, he's the best defensive midfielder in the world. I came here to help the team."
Song also revealed that the chance to play alongside Lionel Messi, whom he labelled "The best player in the world", was too good to turn down - for both his and his children's sake.
"Messi is the best player in the world," he said. "Until now, I could only watch him on TV. Now I'll be able to play with him.
"I have two sons and they admire Messi. They talk about him day in day out. I couldn't refuse this offer. Everything went really fast."