This is quite an engaging documentary that introduces us to four specialist technicians who maintain some of the musical instruments that are provided free to pupils in the Los Angeles school system. Prefaced by a few words from each of the children who benefit from the violins, tubas, pianos and saxophones to name but a few, we then meet four of the people - from a variety of interesting, sometimes quite traumatic, backgrounds - as they show us just how meticulously they work to keep these instruments alive and useful. To be honest, I could have been doing with just a little more performance from the would-be students, but these characters who put their heart and soul into preserving these musical tools come across as dedicated and passionate. The same can be said for the students - especially the young violinist at the start whose smile just about says it all. We end with a rousing section from the alumni of students who have benefitted over the years and this is a fine testament to the role of music in an education system that doesn't just focus on the academic.