Originally a utility player on the fringes of the first team, Song quickly became an integral part of Arsenal's starting 11 during the 2008–09 pre-season, eventually leading to a €15 million transfer to Barcelona in 2012.

Unable to find a club or academy where he could hone his skills, Petit Song (as he is known in the Cameroon side) opted to move to France, joining Bastia at age 16.

[8] In 2011, Song became an ambassador for Grassroot Soccer, an international non-profit organisation working through football to stop the spread of HIV.

During his time at Bastia, he attracted attention from numerous clubs, including Internazionale, Juventus, Manchester United, Lyon and Middlesbrough.

He also started at centre-back in Premier League matches towards the end of the season, most notably in Arsenal's crucial visit to Old Trafford against Manchester United, while regular starter Kolo Touré filled in for Bacary Sagna at right-back.

[19] Song's first league goal, and third in all competitions for the Gunners, was scored against Wigan Athletic on 11 April 2009 in which he took on several players and then coolly finished in the bottom corner.

After putting in consistently commanding performances at the heart of midfield, allowing Arsenal's creative attackers to operate effectively, Song established himself as one of the first names on the team sheet.

[22] In February 2011, Song had his car impounded by Hertfordshire Police after he was caught speeding and failed to provide relevant documentation.

During a league match at Newcastle United, Song stamped on Joey Barton, resulting in him being charged with improper conduct and given a three-match ban.

He provided an assist to Robin van Persie following a dribble for the first goal in a Champions League match against Borussia Dortmund on 23 November to secure a place for Arsenal in the last 16.

[26]Song again assisted Van Persie – who scored a volley – during a match against Everton which also proved to be the only goal as the 125th anniversary game ended 1–0 to Arsenal.

His partnership with striker Van Persie was enhanced in a match on 5 May 2012 as he performed his seemingly trademark chip to assist the Dutchman in netting the equaliser against Norwich City.

[28][29] He made his Barcelona debut against Real Madrid in the 2012 Supercopa de España on 29 August 2012 as a substitute for the last 15 minutes, finishing the match with a perfect passing statistic.

[30] He played 20 matches in Barcelona's La Liga-winning campaign in his first season, and scored one goal, in a 3–1 home win against Real Zaragoza on 17 November 2012.

[31] Song was an unused substitute in the 2014 Copa del Rey Final, which Barcelona lost 2–1 to Real Madrid at the Mestalla Stadium.

[37][38] In August 2015, West Ham co-chairman David Sullivan, announced an agreement with Barcelona to sign Song on a three-year permanent contract subject to a medical.

It was reported on 2 April 2018 that Rubin sent a complaint to the FIFA Dispute Resolution Chamber, demanding 40 million euros from Song for breach of contract.

He played for Cameroon in their first group match, a 4–2 defeat against holders Egypt; he replaced Stéphane Mbia at half time, joining his uncle Rigobert on the pitch.

[58] In the team's second group match, Song was sent off for violent conduct after striking Mario Mandžukić as Cameroon were knocked out, losing 4–0 to Croatia.

[63] In December 2014, despite being in-form for his club West Ham United, he was omitted by Cameroon coach Volker Finke from the squad for the 2015 Africa Cup of Nations.

[64] On 6 January 2015, Song announced his international retirement, aged 27 and earning 49 caps, citing his wish to focus on rebuilding his domestic career with West Ham.

In 2012, former Barcelona goalkeeper and sports director Andoni Zubizarreta described Song as "a player who is good in the air, is physically powerful and tactically astute.