Answer by taking a quote from the following article:

Yusuf Islam (born Steven Demetre Georgiou; 21 July 1948), commonly known by his former stage name Cat Stevens, is a British singer-songwriter and multi-instrumentalist. His 1967 debut album reached the top 10 in the UK, and the album's title song "Matthew and Son" charted at number 2 on the UK Singles Chart. Stevens' albums Tea for the Tillerman (1970) and Teaser and the Firecat (1971) were both certified triple platinum in the US by the RIAA. His musical style consists of folk, pop, rock, and Islamic music.

On 15 September 2014, Yusuf announced the forthcoming release on 27 October 2014 of his new studio album, Tell 'Em I'm Gone, and two short tours: a November 2014 (9-date) Europe tour and a December 2014 (6-date) North America tour, the latter being his first one since 1976. On 4 December 2014, he played to his first public US audience since the 1970s at the Tower Theater in Philadelphia. Yusuf performed two shows in early 2015: on 27 February at the Vina del Mar Festival, Quinta Vergara, Vina del Mar, Chile and on 22 April at the Wales Millennium Centre in Cardiff Bay, area of Cardiff, Wales, UK. On 1 June 2016, Yusuf shared a new song called "He Was Alone" and its corresponding video. Part of his newly launched fundraising campaign for child refugees, #YouAreNotAlone, the song was inspired by a trip to southern Turkey's camps for Syrian refugees. He performed the song live for the first time in a special charity concert, his first show in more than a year, on 14 June 2016 at the Westminster Central Hall in London. On 26 July 2016, Yusuf announced he would be part of the Global Citizen Festival held on 24 September 2016 in Central Park, New York, New York. On 9 August 2016, Yusuf announced "A Cat's Attic Tour", his second North American tour since 1978, beginning on 12 September 2016 at the Sony Centre for the Performing Arts in Toronto and ending on 7 October 2016 at the Pantages Theatre in Los Angeles. The string of 12 dates roughly coincides with the 50th anniversary of his first single, I Love My Dog, and would "feature a limited run of stripped down, introspective performances." The tour included three shows in New York City (two shows at the Beacon Theatre and one show in Central Park at the Global Citizen Festival), his first shows in New York City since 1976. In keeping with his spirit of humanitarianism, he would be donating a portion of the revenue from each ticket sale towards his charity Small Kindness, as well as UNICEF and the International Rescue Committee in an effort to assist children affected by the current Syrian refugee crisis.

What was significant during this time?
Part of his newly launched fundraising campaign for child refugees, #YouAreNotAlone,