What I wrote when I saw it back in '16:
The beauty of Life on a String is that it is rythmic not just in story, but as a whole. Pace, atmosphere, editing, it's all carried on a breeze. The plot is not at the forefront, our senses is. As our old blind protagonist pinches away at his banjo, with the loose promise that he will regain his sight once the 1000th string is broken, the film plays out as the notes of a symphony.
It opens with an otherwordly sight of visual beauty, as one blind master passes the legend on to a young boy. 60 years later the boy is an old weathered man with his own apprentice. He still picking away at his banjo, his life's dedication and sole hope. The people around him view him as a saint, and though blind and desolate he holds the key to life and death in his hands, being able to stop the most heinous acts simply by playing his songs, simply by being present.
In many ways the film can be read as poetry, with it's characters seeming closer to concepts, rather than fully fledged human beings. It perfectly incorporates the old man's songs and music. As he performs it alone, with or for others. As the film in itself feels music, this is never out of place, and simply increased my captivation. It is this very relationship, this worship, his power and his powerlessness, not to mention his mercy and enlightenment in contrast with his blind desperate belief and desire, that makes this portrait so strong.
And then there is the apprentice, with the sole purpose of being the next to lay the banjo, the next to break 1000 strings. He on the other hand is not as blindly devoted, nor in any way revered - and in many ways his presence in itself serves as both a mirror and contrast to the old man, especially when a young woman in introduced. The meditative beauty carries forth, exploring vaste degrees of emotion, and in a way paints a very striking image of humanity as whole.