There's a lot of better ways to do this. For starters, the sp script is bash. He could just edit the script. There's also a function for returning the metadata in machine-parseable syntax:

  function sp-metadata {
    # Prints the currently playing track in a parseable format.
  
    dbus-send                                                                   \
    --print-reply                                  `# We need the reply.`       \
    --dest=$SP_DEST                                                             \
    $SP_PATH                                                                    \
    org.freedesktop.DBus.Properties.Get                                         \
    string:"$SP_MEMB" string:'Metadata'                                         \
    | grep -Ev "^method"                           `# Ignore the first line.`   \
    | grep -Eo '("(.*)")|(\b[0-9][a-zA-Z0-9.]*\b)' `# Filter interesting fiels.`\
    | sed -E '2~2 a|'                              `# Mark odd fields.`         \
    | tr -d '\n'                                   `# Remove all newlines.`     \
    | sed -E 's/\|/\n/g'                           `# Restore newlines.`        \
    | sed -E 's/(xesam:)|(mpris:)//'               `# Remove ns prefixes.`      \
    | sed -E 's/^"//'                              `# Strip leading...`         \
    | sed -E 's/"$//'                              `# ...and trailing quotes.`  \
    | sed -E 's/"+/|/'                             `# Regard "" as seperator.`  \
    | sed -E 's/ +/ /g'                            `# Merge consecutive spaces.`
  }

But as the other replier mentioned, the point was to show off an example of how text manipulation skills can solve many problems, not solve this specific problem in the best way possible.