diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d163863
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build/
\ No newline at end of file
diff --git a/chime8.ogg b/chime8.ogg
new file mode 100644
index 0000000..96174b9
Binary files /dev/null and b/chime8.ogg differ
diff --git a/main.lua b/main.lua
index ed23c41..5d51ff0 100644
--- a/main.lua
+++ b/main.lua
@@ -1,8 +1,15 @@
 local love = love
-local sound
+local sounds = {
+
+
+
+}
 local state = {
 
   isGameStarted = false,
+  beatScoreThreshold = 1.0,
+  currentBeat = 1,
+  startTime = 0.0,
 
   particle = {
     x = 0.0,
@@ -35,9 +42,7 @@ local state = {
 
   beat = {
     t = nil,
-    dt = nil,
     mu = nil,
-    score = 0,
   },
 }
 
@@ -45,74 +50,102 @@ local state = {
 --Reset game state.
 local function NewGame()
   state.beat = {}
-  state.wave.Reset()
+  state.startTime = love.timer.getTime()
+  state.currentBeat = 1
 end
 
-local beat = { }
-local function IsOnBeat( t )
+local function BeatScore( t )
+  local beat = state.beat
+
+  --Base case 1: first tap.
   if not beat.t then
     beat.t = t
-    return true
+    return 2.0
   end
 
-  if not beat.dt then
+  local dt = t - beat.t
+  beat.t = t
 
-
-    local WEIGHT = 0.25
-    beat.mu = ( 1.0 - WEIGHT ) * beat.mu + WEIGHT * dt
-
-
-    if beat.score >= 1.0 then
-      beat.score = 0
-      return true
-    end
-
-    return false
+  --Base case 2: second tap.
+  if not beat.mu then
+    beat.mu = dt
+    return 2.0
   end
 
-  local function OnImpact( impact )
-    --Update beat timer.
-    if not beat then 
-      beat = { mu = 
-      end
-      local dt = impact.t - beat.t
-      beat.t = impact.t
+  --General case: update average beat length.
+  local WEIGHT = 0.25 --High number makes the last beat more significant.
+  local mu = ( 1.0 - WEIGHT ) * beat.mu + WEIGHT * dt
+  beat.mu = mu
 
+  --Safety: avoid a dbz.
+  if mu < 0.001 or dt < 0.001 then
+    error( "DBZ! Beat length too small." )
+  end
 
+  --Calculate beat score.
+  local score = dt * dt / ( mu * mu )
+  local TOLERANCE = 1.15
+  if dt < mu then 
+    return 1.15 * score
+  else
+    return 1.15 / score
+  end
 
+end
 
+local function OnVictory()
 
-      --Handle sound.
-      love.audio.play(sound)
+end
+
+local function OnImpact( impact )
+
+  local score = BeatScore( impact.t )
+  if score > state.beatScoreThreshold then
+
+    state.beatScoreThreshold = 1.0
+    state.currentBeat = state.currentBeat + 1
+    if state.currentBeat >= 120 then
+      return OnVictory()
     end
 
-    local function OnVictory()
+    love.audio.play(sounds.goodPing)
 
-    end
+  else
 
-    function love.draw()
-      love.graphics.setColor(1.0, 1.0, 1.0)
-      love.graphics.print("Hello World!", 400, 300)
-      love.graphics.print( beat.t, 0, 0 )
-      love.graphics.print( beat.dt, 0, 100 )
-      love.graphics.setColor(0, 0.4, 0.4)
-      --love.graphics.circle("fill", 0, 0, 10)
-    end
-
-    function love.load()
-      sound = love.audio.newSource("soundTest.ogg", "static")
-
-      return NewGame()
-
-    end
-
-    function love.update( dt )
-
-    end
+    state.beatScoreThreshold = state.beatScoreThreshold - score
+    love.audio.play(sounds.badPing)
+  end
 
 
-    function love.keypressed( key, code, isRepeat )
-      if key == "escape" then return love.event.quit() end
-      if key == "w" then return OnImpact( ) end
-      if key == "enter" then return NewGame() end
-    end
\ No newline at end of file
+end
+
+
+
+function love.draw()
+  love.graphics.setColor(1.0, 1.0, 1.0)
+  love.graphics.print("Hello World!", 400, 300)
+  love.graphics.print( state.beat.mu or 0, 0, 0, 0, 10, 10 )
+  love.graphics.print( state.beat.t or 0, 0, 100, 0, 10, 10 )
+  love.graphics.print( state.beatScoreThreshold, 0, 200, 0, 10, 10 )
+  love.graphics.setColor(0, 0.4, 0.4)
+  --love.graphics.circle("fill", 0, 0, 10)
+end
+
+function love.load()
+  sounds.goodPing = love.audio.newSource("soundTest.ogg", "static")
+  sounds.badPing = love.audio.newSource("chime8.ogg", "static")
+
+  return NewGame()
+
+end
+
+function love.update( dt )
+
+end
+
+
+function love.keypressed( key, code, isRepeat )
+  if key == "escape" then return love.event.quit() end
+  if key == "w" then return OnImpact{ t = love.timer.getTime() } end
+  if key == "enter" then return NewGame() end
+end
\ No newline at end of file