r := RandomChoice[{1, 5, 6}]
g[x_] := 
  RandomChoice[{0.5, 0.3, 0.2} -> {x, {x[[1]]}, {x[[1]], x[[2]]}}];
accord := Module[{}, r1 = r; {{1 + r1, 5 + r1, 6 + r1}, {1, 5, 6}}];
scale = {1 + r, 5 + r, 6 + r};
s := g[RandomChoice[accord]] + RandomChoice[scale]
A = Table[{s, Random[Integer, 3] + 1}, {40}];
sn[{a_, t_}] := SoundNote[s, t];
song2 = Sound[{"Violin", sn /@ A}, 30]
Export["alex_hugon.midi", song2, "Midi"]