Adopting the same strategy that secured Cesc Fabregas last year, the Catalans have provisionally agreed personal terms with Song ahead of lodging a formal offer for his transfer.
The versatile Cameroon international has been promised a five-year contract at Camp Nou with an annual salary of ?5 million (Dh22.5m) gross. Insiders say the club will discuss a transfer fee with Arsenal next week.
Barca turned to Song after Paris Saint-Germain deflected their year-long pursuit of Thiago Silva by paying AC Milan ?42m for the Brazil defender and Athletic Bilbao refused to sell Javi Martinez for less than the Spain international's ?40m buyout clause.
Tito Vilanova, who has succeeded Pep Guardiola as Barca coach, is driving the pursuit of Song. The 24-year-old African is capable of playing both in the heart of the defence and in front of it. Song's passing ability, which is critical to the Catalans' style, was underlined by his 11 Premier League assists last season, a total bettered only by David Silva, Juan Mata and Antonio Valencia.
Arsene Wenger is well aware of Barca's interest and though he will resist a sale has instructed his scouting staff to assess possible replacements. Three of Arsenal's senior scouts watched Celtic midfielder Victor Wanyama in the space of eight days last month, and Nuri Sahin, who is surplus to requirements at Real Madrid, is also under consideration.
Undermined by the protracted exits of Fabregas and Samir Nasri last summer and prepared for Robin van Persie to force his own departure this, Wenger has operated a proactive transfer strategy this summer. Lukas Podoloski and Olivier Giroud were subsequently purchased from Cologne and Montpellier respectively as substitutes for his unsettled club captain.
With Santi Cazorla also extracted from Malaga, Wenger is attempting to hold onto both Van Persie and Song but the Gunners board, however, take a more pragmatic view of raising revenue from transfers, and both Manchester City and United expect Van Persie to be sold for significantly less than Wenger's £30m (Dh171.6m) asking price.
Barcelona are not in a position of great financial strength having announced Vilanova's appointment before agreeing the new coach's salary and negotiating a first option on the future transfer of the Brazil forward Neymar, for which they paid Santos an initial ?10m. As a result, Barca president Sandro Rosell has set a ceiling of ?18m for the purchase of Song.
As is also customary in Barcelona's transfer tactics, senior players are already talking openly about Song's acquisition.
"I have followed his career and he has become a very good player," said Gerard Pique yesterday. "He is physically very strong and is good with the ball at his feet. We are open to his arrival. If he comes, and from what I have read he could do, we would love to have him."
One Arsenal player who will ply his trade in the Primera Liga this season is the striker Carlos Vela, who has joined Real Sociedad for an undisclosed fee.
Follow us @SprtNationalUAE