diff --git a/pulsar.p8 b/pulsar.p8
index b5a69fe..3be02fb 100644
--- a/pulsar.p8
+++ b/pulsar.p8
@@ -2,8 +2,10 @@ pico-8 cartridge // http://www.pico-8.com
 version 42
 __lua__
 #include shared/_meta.lua
+#include shared/instrument.lua
 #include shared/nflags.lua
 #include shared/pattern.lua
+#include shared/performer.lua
 #include shared/pflags.lua
 #include shared/track.lua
 #include unique.lua
@@ -15,10 +17,11 @@ __gfx__
 00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
 00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
 __sfx__
-010f2000000500c05007055030421c03028030230351f022000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
-010f20000000007040130400e0450a032230302f0302a035260220000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+010f20001e2241e2201e22525224252202522523224232222322521224202241e2241c2241c2251a2241a22519224192201922023224232202322022224222222222222225000001c2241e224202242122423224
+010f2000252242522523224232252a2242a2252c2242c2252d2242d2252f2242d2242c2242c2252a2242a22528224282252a22428224262242622528224262242522425220252202522500000000000000000000
 010f200000000000000e0401a04015045110322a03036030310352d02200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
 010f200000000000000000015040210401c04518032310203d0203802534012000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
 __music__
-00 00010203
+00 00404040
+00 01404040
 
diff --git a/shared/instrument.lua b/shared/instrument.lua
new file mode 100644
index 0000000..11909c5
--- /dev/null
+++ b/shared/instrument.lua
@@ -0,0 +1,31 @@
+instrument=klass()
+function instrument:init(callback)
+ self.callback=callback
+ self.volume=1.0
+end
+
+function instrument:spackle(track,channel,t0,t1,note,verbs)
+ -- a one-indexed table of note data
+ -- (one-indexed because Lua kind of sucks)
+ local nflagses,keep_silence=self.callback(t1-t0,note,instrument_split_verbs(verbs))
+ for i,nflags in pairs(nflagses) do
+  if nflags.v>0 or keep_silence then
+   nflags = nflags:clone()  -- avoid breaking instrument
+
+   local min_v=0
+   if (nflags.v>0) min_v = 1
+   nflags.v = mid(flr(nflags.v * self.volume + 0.5),min_v,7)
+
+   track:plot(channel,t0+i-1,nflags)
+  end
+ end
+end
+
+instrument_split_verbs=function(x)
+ if (not x) return {}
+ local t={}
+ for i in all(split(x)) do
+  t[i]=true
+ end
+ return t
+end
\ No newline at end of file
diff --git a/shared/nflags.lua b/shared/nflags.lua
index 588cd7b..d4db462 100644
--- a/shared/nflags.lua
+++ b/shared/nflags.lua
@@ -9,6 +9,10 @@ function nflags:init(o)
  self:validate()
 end
 
+function nflags:clone()
+ return nflags:new(self)
+end
+
 function nflags:validate()
  local c,e,v,w,p
   =self.c,self.e,self.v,self.w,self.p
diff --git a/shared/performer.lua b/shared/performer.lua
new file mode 100644
index 0000000..060acb4
--- /dev/null
+++ b/shared/performer.lua
@@ -0,0 +1,28 @@
+performer=klass()
+function performer:init(track,channel,instrument,time,roots)
+ assert_range(#roots,1,33,"#roots")
+
+ self.track=track
+ self.channel=channel
+ self.instrument=instrument
+ self.time=time
+ self.roots=roots
+ self.selected_root=1
+end
+
+function performer:root(root)
+ assert_range(root,1,#self.roots,"root")
+ self.selected_root=root
+end
+function performer:play(duration,note,verbs)
+ local base=self.roots[self.selected_root]
+ local note=base+note
+ local t0=self.time
+ local t1=t0+duration
+ self.time+=duration
+ self.instrument:spackle(self.track,self.channel,t0,t1,note,verbs)
+end
+function performer:rest(duration)
+ self.time+=duration
+end
+
diff --git a/shared/track.lua b/shared/track.lua
index a7a0407..c754bb2 100644
--- a/shared/track.lua
+++ b/shared/track.lua
@@ -31,13 +31,13 @@ function track:pattern(channel,offset)
  return self.frames[offset+1][channel+1]
 end
 
-function track:plot(channel,offset,inst)
+function track:plot(channel,offset,ndata)
  assert_range(channel,0,4,"channel")
  assert_range(offset,0,self.next_frame_start,"offset")
  local tup=self.ix_to_frame[offset]
  assert(tup)  -- should be unable to fail
  local frame,offset=unpack(tup)
- self.frames[frame+1][channel+1]:plot(offset,inst)
+ self.frames[frame+1][channel+1]:plot(offset,ndata)
 end
 
 function track:build(
@@ -73,6 +73,6 @@ function track:build(
   for i=0,3 do
    poke(fmaddr+i,map_to_real_pattern(self.frames[frame][i+1]))
   end
-  fmaddr+=1
+  fmaddr+=4
  end
 end
\ No newline at end of file
diff --git a/unique.lua b/unique.lua
index 34b55a7..ca20fb5 100644
--- a/unique.lua
+++ b/unique.lua
@@ -18,20 +18,60 @@ end
 function build_bgm()
  local bgm=track:new()
 
+ bgm:add(32)
  bgm:add(32)
 
- local root=0
- for chan=0,7 do
-  local p=root+chan*7
-  local start=0+chan*1
-  local v=5-chan/3
-  local c=chan%4
-  bgm:plot(c,start+0,{v=v,p=p})
-  bgm:plot(c,start+1,{v=v,p=p+12})
-  bgm:plot(c,start+2,{v=v,p=p+7,e=5})
-  bgm:plot(c,start+3,{v=v-1,p=p+3,e=2})
-  -- bgm:plot(c,start+4,{v=v-1,p=p})
- end
+ 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
\ No newline at end of file
+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