function _init()
 local bgm=build_bgm()
 local free_patterns={}
 for i=0,63 do add(free_patterns,i) end

 bgm:build(free_patterns,0)

 cstore(0x3100,0x3100,0x1200)
 music(0)
end
function _update()
end
function _draw()
 cls(0)
 print("enjoy the music!")
end

function build_bgm()
 local bgm=track:new()

 bgm:add(32)
 bgm:add(32)

 trumpet=instrument:new(play_trumpet)
 local perf=performer:new(bgm,0,trumpet,0,{30})
 perf:play(3,0)
 perf:play(3,7)
 perf:play(3,5,"warb")
 perf:play(1,3)
 perf:play(1,2)
 perf:play(1,0)
 perf:play(2,-2)
 perf:play(2,-4)
 perf:play(3,-5,"hold")
 perf:play(3,5,"hold")
 perf:play(4,4,"warb")
 perf:rest(1)
 perf:play(1,-2)
 perf:play(1,0)
 perf:play(1,2)
 perf:play(1,3)
 perf:play(1,5)

 perf:play(2,7)
 perf:play(2,5)
 perf:play(2,12)
 perf:play(2,14)
 perf:play(2,15)
 perf:play(1,17)
 perf:play(1,15)
 perf:play(2,14)
 perf:play(2,12)
 perf:play(2,10)
 perf:play(1,12)
 perf:play(1,10)
 perf:play(2,8)
 perf:play(1,10)
 perf:play(1,8)
 perf:play(4,7)
 perf:rest(4)

 return bgm
end

function play_trumpet(duration,pitch,verbs)
 local e=0
 if (verbs.slide) e=1
 if (verbs.warb) e=2

 local out={}
 for i=1,duration do
  out[i]=nflags:new{p=pitch,v=2,w=2,e=e}
 end
 if (not verbs.slide) out[1].e=4
 if (not verbs.hold and #out>1) out[#out].e=5
 return out
end