Condense

tArgs = { ... }
if not tArgs[2] then tArgs[2] = tArgs[1] .. ".song" end
file2 = fs.open(tArgs[2],"a")
lines = io.lines(tArgs[1])
print("Target: " .. tArgs[1])
print("Output: " .. tArgs[2])
print("Working...")
term.setTextColor(colours.orange)
for line in lines do
    if line:find("playNote") then
      a1,a2 = line:find("(",0,true)
      b1,b2 = line:find(",",a2+1,true)
      c1,c2 = line:find(")",a2+1,true)
      if b1 then
        arg1 = line:sub(a2+1,b1-1)
      else
        arg1 = line:sub(a2+1,c1-1)
      end
      if b1 then
        arg2 = line:sub(b2+1,c1-1)
      end
      arg2 = arg2:gsub(" ","")
      if arg2 then
        file2.writeLine("P|" .. arg1 .. "|" .. arg2)
      else
        file2.writeLine("P|" .. arg1)
      end
    elseif line:find("sleep") then
      local a1,a2 = line:find("(",0,true)
      local b1,b2 = line:find(")",0,true)
      local arg1 = line:sub(a2+1,b1-1)
      file2.writeLine("S|" .. arg1)
    end
end
term.setTextColor(colours.white)
print("Done")
file2.flush()