Overview:

  The wise needs a set of audio-samples; these are the sounds-files
  (recorded or generated) of each of the holes of your harmonica;
  blow, draw, bend.
  
  The samples are used to:
  
  - Play a series of holes, e.g. for modes play or quiz
  - Judge the frequencies of your playing against the frequencies of the
    samples to find out, which note you are actually playing

  You may either record those samples under the guidance of this mode,
  or you may let the wise generate them for you; adding some helper
  functions, this gives the following choice of extra arguments:

<%= get_extra_desc_all(for_usage: true).join("\n") %>


  The samples need to be generated for each key, but only once in the
  lifetime of your harp; you may start with the key of c only.
  After that you are ready to use the other modes of the wise.

  Samples that have been recorded will not be overwritten with
  samples, that the wise generates.  Moreover, recorded samples are
  always preferred over generated samples, when harpwise has to play
  holes; remove recorded samples, if (for the moment) you prefer
  generated samples.
  
  By its nature, this mode only accepts arguments for type and key,
  but not for scale.
  

Usage by Examples:

  Record samples to teach the wise abut the frequencies of the harp
  you are using:

    harpwise samples c record

  this will ask you to play notes on your harp (key of c). The samples
  will be stored in the hidden folder .harpwise within your home
  directory; frequencies will be extracted to the file
  frequencies.yaml.

  You may cancel the process of recording samples after any hole whle
  still keeping the samples recorded so far (but you may 'delete'
  them, if you choose). If later, you want to continue recording from
  where you left, simply give the respective hole as an argument, e.g.

    harpwise samples c record +4


  If at a later time, you just want to review the samples, you have
  created, simply use play, e.g.:

    harpwise play +4

  or even:

    harpwise play all


  Compared with the process of recording samples, the alternative of
  generating samples automatically is the quickest way to get started.
  The wise may create all the audio samples for you (using sox);
  however, this cannot match the characteristics of your own harp and
  your own playing style, but it gives a good quick start.  For
  auto-generation, type:

    harpwise samples a generate


  Or, to generate everything, all holes, all keys, in a single run:

    harpwise samples generate all

  With this, only when first changing the type of harmonica, e.g. from
  richter (default) to chromatic, you will need to create samples
  again.


  If later, you want to remove some samples, that you have recorded
  previously, try (for the key of d):

    harpwise samples d delete

  this applies to recorded samples only; there is no need to delete
  generated samples, as they can allways be generated and overwritten
  or shadowed by recorded samples.
  
