code: function fromFreq (freq, tuning) {
    tuning = tuning || 440
    var lineal = 12 * ((Math.log(freq) - Math.log(tuning)) / Math.log(2))
    var midi = Math.round(69 + lineal)
    return fromMidi(midi)
  }
docs: Get the pitch of a given frequency.
  
  It will round the frequency to the nearest pitch frequency. Use `cents` function
  if you need to know the difference between the the frequency and the pitch.
  
  @param {Float} freq - the frequency
  @return {String} the pitch
  
  @see cents
  
  @example
  pitch.fromFreq(440) // => 'A4'
  pitch.fromFreq(443) // => 'A4'
  pitch.cents(443, 'A4') // => ... to get the difference