In 1931, during the Depression, an unknown young black woman took her new-born son to a Pittsburgh orphanage. And so began jazz pianist Horace Parlan´s life. At the age of five, he was struck by polio and lost the use of three fingers on his right hand, yet somehow, against the odds, he managed a long career as a professional musician.

In Ukraine, whilst she reported on MH17, a miner gave the ID of a passenger to Natalia Antelava. A year on, she meets the passenger’s sister, and tries to find the miner.

Izzat Majeed could have retired quietly, but instead he formed the Sachal Jazz Ensemble.

Kuba Nowak lives in London’s East End, a fast-changing part of the city. He loves his street and his neighbours, many of whom have lived there most of their lives. Together they celebrate their community by planting trees, sharing produce from their gardens and holding regular street parties with food, music and dancing. Now rising property prices and new development mean the neighbourhood is changing so rapidly that residents scarcely recognise the place they live.

Denmark’s second city has been attracting attention for its project to prevent its young people from going to Syria to fight for Islamic State. Is the Aarhus Model working?

Headhunters deal in high-value, high-profile appointments, charging an equally high fee. But few companies or individuals like to openly acknowledge their work. Why would a company need outside consultants to search its own backyard, as some do? Jolyon Jenkins follows academic headhunter Helen Yallop as she searches for a Master for an Oxbridge college, and gains a a fascinating insight into a hidden world.

David Stern examines the causes and consequences of Ukraine’s other crisis – its demographic timebomb. The country’s population once stood at over 50 million but it has fallen sharply and some projections put it at only 32 million by 2050. Few if any countries have gone through such precipitous population loss. Will demography, rather than war, mean the death of Ukraine?

Neal Razzell reports from the Estonian city of Narva, which is in NATO but almost entirely Russian. Could this be the west’s weak spot? Here, the Estonian government says, Moscow is trying to destabilise it by exploiting local grievances – just as NATO says it did in Ukraine. So Estonia is mounting an urgent campaign to win hearts and minds among its Russian population. Ethnic Russians account for a quarter of all Estonians, and most say their economic prospects are best served by living in the west. But many are also profoundly ambivalent about their identity, culturally and linguistically at odds with the majority, and asking questions about what it means to be an Estonian. Produced by Michael Gallagher

German comedian Henning Wehn explores the growing use of ELF – English as a lingua franca. He talks to academics and consultants in the fast-growing field of ELF and learns that it is rapidly developing a grammar and structure of its own – often not understood by those who have grown up speaking English.

Interpol is the world's biggest and most powerful international policing organisation. Spanning almost every existing country - with the notable exception of North Korea - it carries out vital work in combatting worldwide organised crime. Increasingly important in our globalised era, but lacking in accountability and surrounded with an aura of mystery, it has to cope with new scrutiny. In this age of accountability and transparency, how long can it withstand demands for change?