# Music Management Scripts

This repo contains a bunch of scripts for fetching, tagging and organising a
music collection. It makes lots of assumptions about the directory structure,
mount points, etc. so it's probably more useful for copy/paste than for
download/execute.

Each script might be useful on its own, but a few useful "workflows" have
emerged.

NOTE: You should never need to run a script directly from this repo. Instead,
use `nix-build` to create a "bin" directory and run them from there; that will
ensure their dependencies are wired-in.

## Fixing a Music Collection ##

Most scripts deal with "fixing" one aspect or another of a music collection,
e.g. finding potential duplicates, moving tracks into album-appropriate
directories, spotting non-music cruft, etc.

The main entry point for coordinating all of this is `fix-music`. This should be
run with `~/Public` as the current working directory (i.e. the `/opt/shared`
directory of the raspberry pi). The only "actions" this script will take are to
download metadata and cache CRCs and AcoustIDs. Everything else is simply
printed to stdout; it is up to us whether we want to follow those
recommendations.

## Getting Music ##

The main script for this is `get_album`, which will download and tag the content
of a YouTube playlist. This performs a lot of I/O, to download, then extract
audio, then add artist tags, then add album tags; so it's recommended to do it
locally, in `~/Downloads/Music`, rather than over SSHFS or such.

Alternatively, to get a single track from YouTube or other site, we can use
`yt-audio`, which is a simple wrapper around `youtube-dl` with sensible
defaults.

Once we've got a bunch of music, we should tag it using something like Picard;
the artist and album tags added by `get_album` are often sufficient to make the
MusicBrainz lookup work.

Tags should be saved in files (Options -> Save Tags), and files should be
renamed (Options -> Rename Files) to the following format:

    $if($gt(%totaldiscs%,1),%discnumber%-,)$num(%tracknumber%,2) %title%

For example `1-04 My Favourite Song.opus` where `1-` is the disc number (iff
there is more than one), `04` is the track number, `My Favourite Song` is the
track title and `opus` is the audio format.

We do not currently use Picard to move files (i.e. we *do not* use
Options -> Move Files).

Once we have fixed up these files locally, we can copy them over the the
raspberry pi using the `move_downloaded_music` script.