1384: Letters from Barcelona. An experiment sonifying the metadata in an archive. Listen at https://soundcloud.com/fhg1711/1384-letters-from-barcelona-sonification-version

barcelona.rb

# 1384: Letters from Barcelona - sonification version
# Data is travel time from Barcelona to Pisa and Barcelona to Avignon for letters (piano: to Pisa; string pluck: to Avignon). Duration is a function of the travel time scaled to 4 beats = 2 weeks. Notes are scored to correspond with the start date; pitch is a function of duration it took for the letter to reach its destination, so silences are meaningful. Longer journeys have higher and longer tones. The percussion plays the beat so that we can hear the progression of time; there is a background drone to indicate the passage of months.
# this code was rubber-ducked using GPT4-preview
require 'date'
ba_data = [9,9,8,7,9,8,8,8,12,9,8,9,10,8,8,8,8,11] #barcelona - avignon
ba_data_trip_start_date = ["1384-05-02","1384-05-09","1384-05-12","1384-05-20","1384-05-23","1384-05-26","1384-06-03","1384-06-15","1384-06-23","1384-07-11","1384-08-02","1384-08-06","1384-08-12","1384-09-01","1384-09-06","1384-09-06","1384-09-12","1384-09-19"]

bp_data = [26,22,34,23,23,21,30,26,24,14,30,19,7,28,25,22,48,22,23,29,16,33,31,44,41,10] #barcelona - pisa
bp_data_trip_start_date = ["1384-01-04","1384-01-22","1384-01-28","1384-02-08","1384-02-11","1384-02-13","1384-02-15","1384-02-19","1384-02-24","1384-03-11","1384-04-05","1384-04-29","1384-04-30","1384-05-09","1384-05-17","1384-05-26","1384-06-23","1384-07-02","1384-07-11","1384-08-06","1384-09-26","1384-11-11","1384-12-13","1384-12-19","1384-12-22","1384-12-29"]


# Trigger date to start playing notes from
trigger_date = "1384-01-01"
# 4 beats = 2 week
days_per_four_beats = 14

define :median do |values|
  sorted = values.sort
  len = sorted.length
  (sorted[(len - 1) / 2] + sorted[len / 2]) / 2.0
end

define :map_to_scale do |value, data, octave|
  median_value = median(data)
  scale_size = scale(octave, :minor_pentatonic).size
  middle_index = scale_size / 2
  index_offset = (value - median_value).round
  middle_index + index_offset
end

define :time_to_beats do |time_in_days|
  beats_per_day = 4.0 / days_per_four_beats
  time_in_days * beats_per_day
end

define :date_to_days do |start_date, date|
  (Date.parse(date) - Date.parse(start_date)).to_i
end

define :schedule_note do |zipped_data, synth_type, synth_opts|
  use_bpm 240 # Marching tempo
  
  in_thread(name: synth_opts[:name]) do
    zipped_data.each do |value, date|
      days_since_trigger = date_to_days(trigger_date, date)
      sleep days_since_trigger * (4.0 / days_per_four_beats) if days_since_trigger > 0 # Convert days since trigger to beats
      note_duration = time_to_beats(value)
      
      scale_notes = scale(:eb3, :minor_pentatonic)
      note_index = map_to_scale(value, zipped_data.map(&:first), :eb3)
      note_index %= scale_notes.size
      note = scale_notes[note_index]
      
      synth synth_type, {note: note, sustain: note_duration, release: 0.1}.merge(synth_opts)
      
      sleep note_duration
    end
  end
end

define :play_monthly_voice do |trigger_date, scale_notes, synth_opts|
  use_bpm 240 # Set BPM to make a beat equal to a day
  beats_per_month = 16 # 4 weeks per month, 4 beats per week
  
  in_thread(name: synth_opts[:name]) do
    # Calculate total number of months based on the max 'days_since_trigger' for all trips
    max_days_since_trigger = [bp_data_trip_start_date, ba_data_trip_start_date].flatten.max_by { |date| date_to_days(trigger_date, date) }
    total_months = (date_to_days(trigger_date, max_days_since_trigger) / 30.0).ceil
    
    # Play a note starting at the bottom of the scale and moving up in thirds every month
    total_months.times do |month|
      note_index = month * 1 # 2 Moving up by thirds in a scale is equivalent to skipping one note each time
      note = scale_notes[note_index % scale_notes.size] # Ensure we loop back to the start of the scale if we run out of notes
      octave_adjustment = (note_index / scale_notes.size) * 12 # Adjust the octave if we've looped the scale
      adjusted_note = note + octave_adjustment
      
      synth :winwood_lead, {note: adjusted_note, sustain: beats_per_month - 1, release: 1}.merge(synth_opts) # Play the note with the passed synth options
      sleep beats_per_month # Wait for the next month
    end
  end
end

scale_notes = scale(:eb2, :minor_pentatonic) # Start at the bottom of the scale
play_monthly_voice(trigger_date, scale_notes, {name: :monthly_voice, amp: 0.1})

# Precompute zipped data for Barcelona-Pisa
bp_zipped_data = bp_data.zip(bp_data_trip_start_date)
bp_zipped_data_sorted = bp_zipped_data.sort_by { |_, date| Date.parse(date) }

# Precompute zipped data for Barcelona-Avignon
ba_zipped_data = ba_data.zip(ba_data_trip_start_date)
ba_zipped_data_sorted = ba_zipped_data.sort_by { |_, date| Date.parse(date) }

# Schedule the voices using precomputed zipped data
schedule_note(bp_zipped_data_sorted, :piano, {name: :piano_voice, amp: 0.9, pan: -0.5, release: 0.3})
schedule_note(ba_zipped_data_sorted, :pluck, {name: :pluck_voice, amp: 0.9, pan: 0.5, release: 0.3})

# Background sostenuto voices using precomputed zipped data
schedule_note(bp_zipped_data_sorted, :prophet, {name: :prophet_voice, amp: 0.2, pan: -0.5, attack: 1, sustain: 4})
schedule_note(ba_zipped_data_sorted, :saw, {name: :saw_voice, amp: 0.2, pan: 0.5, attack: 1, sustain: 4})

# percussion # straight march
live_loop :march_drumming do
  sample :bd_ada, amp: 0.5
  sleep 1
  sample :drum_bass_soft, amp: 0.5
  sleep 1
  sample :bd_ada, amp: 0.3
  sleep 1
  sample :drum_snare_hard, amp: 0.5
  sleep 1
end