The reindeer play a central role in the livelihoods and culture of the indigenous people of the region, the Sami, but this way of lifeis under pressure, as I saw on ajourney in northern Norway earlier this month.
The track is featured on his latest album Joko, a musical journey from life in his parents' village to his collaborations with western artists including Gabriel, Sting and Fugee Wyclef Jean.
The first part of the answer is easy: until life improves in the Mexican countryside, there will always be migrants ready to undertake a perilous journey north.