{{- $tracks := slice -}}
{{- range .Pages -}}
  {{- $track := dict
    "title" .Title
    "url" .Permalink
    "slug" .File.ContentBaseName
    "audio" .Params.audio
    "duration" .Params.duration
    "genre" .Params.genre
    "image" ""
  -}}
  {{- with .Resources.GetMatch "cover.*" -}}
    {{- $img := .Resize "200x webp q85" -}}
    {{- $track = merge $track (dict "image" $img.RelPermalink) -}}
  {{- end -}}
  {{- $tracks = $tracks | append $track -}}
{{- end -}}
{{- dict "tracks" $tracks | jsonify (dict "indent" "  ") -}}