Simple script in ruby which schedules genres of musica by hour. Personally I call it with mpdcron.

mpdsched

#!/usr/bin/env ruby

require 'ruby-mpd'

mpd = MPD.new
mpd.connect

sched = ['Jazz', 'Jazz', 'Classical', 'Classical', 'Country', 'Blues', 'Son Jarocho', 'Jazz', 'Classical', 'Classical', 'Country', 'Blues', 'Jazz', 'Soul', 'R&B', 'R&B', 'Chilena', 'African', 'Afrobeat', 'Cumbia', 'Salsa', 'Tropical', 'Salsa' ,'Classical'] # 0-24

# make list of filenames w/out extension
queue = mpd.queue.map {|x| x.file[/.*(?=\..+$)/]}.compact
time = Time.now + 900 # offset to account for queue length

# loop util we get a song which is not already in the playlist, removing file extensions
i = 0
while i == 0
  s =  mpd.search(:genre, sched[time.hour], :case_sensitive => false).sample
  p "[try] #{s.file[/.*(?=\..+$)/]}"
  unless queue.include?(s.file[/.*(?=\..+$)/])
    p "[add] #{s.file[/.*(?=\..+$)/]}"
    mpd.add s.file
    i = 1
  end
end