Berlusconi: A New Musical, an excellent title, has opened at a new venue in south London, Southwark Playhouse Elephant. The show begins with the former Italian prime minister preening triumphantly on a white marble set that resembles the Capitol in Rome where Caesar was murdered by rivals who’d grown sick of his power lust. Berlusconi introduces us to his nemesis, a state prosecutor called Ilda Boccassini, who pursues him for years through the courts. With typical coarseness he dismisses her as a ‘haggard old sow’. And yet the pair perform a strange romantic dance that culminates in a bizarre Berlusconi chat-up line: ‘If you weren’t so frigid we’d end up in bed.’ Misogyny is his defining characteristic. Gallantry and charm are alien to him. In flashback scenes we watch his mother advising her young son ‘to do good’ and to become a conqueror. At least he got it half right. He was influenced by his early success as a tenor on a cruise ship where he learned to seduce the female passengers and his hapless backing singers. That experience taught him to view women as trophies, baby-machines or comfort girls. His father was a Fred Trump figure who persuaded his son to move into real estate and helped him make a fortune building blocks of flats in Milan. Berlusconi used his wealth to set up a private TV channel whose content was defiantly vulgar. Berlusconi said he was proud to have added Dallas and topless darts to the cultural wonders of Italy.

The dramatic hook of the show is his prosecution in October 2012 on charges of embezzlement, abuse of public office and so on. He sees the trial as yet another opportunity to dazzle his supporters and he prepares for his court appearance by getting his saggy face injected with enough shots of Botox to fell an elephant. As the prosecutor reads out the charge sheet he nods and smirks with approval, glorying openly in his misdeeds. This heartless, egoistical side of his character never receives any softening touches of self-doubt or modesty. Callous to the core. That’s him. The show is a useful revision tool for anyone studying recent Italian politics but as a character study it’s deeply unsatisfying. The women in Berlusconi’s life allow him to treat them as disposable sex dolls and their capitulation to his will merely strengthens his view of himself as a flashy, faultless demi-god. His very first line, ‘I’m the Jesus Christ of politics’, sums up his self-deceiving megalomania. It’s the opposite of the truth. Christ preached humility. Berlusconi preached humility for his followers and his gullible victims but not himself.

Gone Too Far!, written by Bola Agbaje in 2007, is now a GCSE set text but don’t let that put you off. The revival at Stratford East, directed by Monique Touko, hits all the right notes in this oddball comedy of manners set on the streets of south London. The show could almost be a rewrite of Jeeves and Wooster.

The opening scene is audaciously banal. Two brothers of Nigerian extraction are sent by their mother to fetch a pint of milk and their errand turns into a cultural odyssey through the dangerous underworld of Peckham. The younger brother, Yemi, feels at ease in the neighbourhood where he grew up but his older brother, Ikudayisi, recently arrived in London from Nigeria, seems clueless and awkward. His Matalan clothes look cheap and unfashionable. His friendly innocence is taken as a sign of weakness. And his broad African accent, peppered with Yoruba jargon, embarrasses Yemi. Black youngsters never use their parents’ language in public. So when Ikudayisi offers to teach Yemi to speak Yoruba the answer is an angry ‘no way’. But later, Yemi hears a gang leader using the mother tongue to Ikudayisi so he changes his mind and becomes an avid language student.

The plot turns on small but seismic moments like this. Yemi’s circle includes an angry mixed-race girl, Armani, who boasts of her Jamaican heritage even though she has yet to visit the Caribbean. And her English mother doesn’t understand West Indian cuisine and can cook only ‘beans on toast’. When this secret is exposed, Armani suffers paroxysms of shame. The play takes the viewer into a delicate, multilayered society where vendettas and love affairs are pursued according to strict conventions of speech, diet and dress.

The second act contains a brilliantly orchestrated knife fight in which the blade changes hands three times and the least aggressive character ends up stabbed. The scene has the weird and gripping unpredictability of real life. And though the story embraces the violent realities of the inner city, it finds a note of tender reconciliation at the end. The brothers learn. They grow. They hug. Scripts that finish like that are usually nauseating but this is different. It’s a classic.