code: def find_with_extension(in_dir, ext, depth=3, sort=True):
      
      assert depth >= 1
      ext = ext.strip(os.extsep)
      match = list()
      for n in range(1, depth+1):
          wildcard = os.path.sep.join(["*"]*n)
          search_path = os.path.join(in_dir, os.extsep.join([wildcard, ext]))
          match += glob.glob(search_path)
  
      if sort:
          match.sort()
      return match
docs: Naive depth-search into a directory for files with a given extension.
  
      Parameters
      ----------
      in_dir : str
          Path to search.
      ext : str
          File extension to match.
      depth : int
          Depth of directories to search.
      sort : bool
          Sort the list alphabetically
  
      Returns
      -------
      matched : list
          Collection of matching file paths.
  
      Examples
      --------
      >>> jams.util.find_with_extension('Audio', 'wav')
      ['Audio/LizNelson_Rainfall/LizNelson_Rainfall_MIX.wav',
       'Audio/LizNelson_Rainfall/LizNelson_Rainfall_RAW/LizNelson_Rainfall_RAW_01_01.wav',
       'Audio/LizNelson_Rainfall/LizNelson_Rainfall_RAW/LizNelson_Rainfall_RAW_02_01.wav',
       ...
       'Audio/Phoenix_ScotchMorris/Phoenix_ScotchMorris_STEMS/Phoenix_ScotchMorris_STEM_02.wav',
       'Audio/Phoenix_ScotchMorris/Phoenix_ScotchMorris_STEMS/Phoenix_ScotchMorris_STEM_03.wav',
      'Audio/Phoenix_ScotchMorris/Phoenix_ScotchMorris_STEMS/Phoenix_ScotchMorris_STEM_04.wav']