California filmmaker Mark Johnson spent 10 months connecting musicians from 20 countries through laptop mini-studios powered by car batteries. The results of that musical collaboration appear on PFC2: Songs Around the World, the second collection by Johnson's Playing for Change Foundation. It will be released May 31.

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The Playing for Change Foundation uses proceeds from its videos, recordings and tours to sustain seven music schools in Africa and Nepal, where 130 teachers are teaching 700 students. Launched in 2007, the nonprofit upholds local traditions, creates much-needed jobs and brings together musicians and students from disparate cultures.

Each one of the songs from around the world blends beautifully filmed performances from different parts of the globe. The version of Bob Marley's "Three Little Birds" brings together musicians in Mali, New York, Los Angeles, Jamaica, India, Paris, Senegal and Ghana.

To date, more than 30 million YouTube viewers have seen Playing for Change's debut video, "Stand By Me," since Johnson first recorded street musician Roger Riddley singing it in Santa Monica five years ago. Johnson remembers the day well. "I asked Roger, 'With a voice like yours, why are you singing in the street?' Roger replied, 'Man, I'm in the joy business. I come out here to bring joy to people.' And that's kind of been our mantra from the beginning: to stay true to people in the joy business and to try to find positivity around the world."

The project also has its distinct challenges. "When we were recording music in the Himalayas," Johnson recalls, "I bought a charged car battery, got to the top of the mountain, realized it actually wasn't charged and had to hump it back down."

In Colombia, Johnson's crew was asked to help unite a country that's been at war with itself for 50 years, "so the country could feel pride rather than despair." Parts of "La Tierra del Olvido" ("Land of the Forgotten") on PFC2 were recorded under wartime conditions. Hearing that rebels were approaching during one session, Johnson says, "I never rolled up a mike cable faster in my life."