Play Intro Sound when Home Assistant turns (Kodi) Home Cinema on?

Hi there,
I am new to HA and am struggling with the last step of my “turn home cinema on” script I made with Home Assistant. Maybe one of you guys have an idea here.
I want to play a THX/Dolby Atmos theme (mp3) when the script is triggered. Here I dont know how to approach this. I am using a Vero4K with OSMC (Kodi Fork) as media client and a Intel NUC with OpenMediaVault (Debian Core) and Plex as media server. Furthermore a Pioneer LSX701 (AVR) and a Logitech Harmony Hub are present as relevant hardware.
The script until here:

'1575806592249':
  alias: Cinema Night
  sequence:
  - device_id: ab2810ef395a4c72b55a968cd59a3b36
    domain: switch
    entity_id: switch.backplug
    type: turn_on
  - delay: 00:00:01
  - alias: 'Beamer On'
    data:
      command: PowerOn
      device: 65245933
      entity_id: remote.harmonyhub
    service: remote.send_command
  - alias: 'AVR2 On'
    data:
      command: PowerOn
      device: 65261054
      entity_id: remote.harmonyhub
    service: remote.send_command
 - alias: 'Source Vero4K'
    data:
      entity_id: media_player.pionner_avr
      source: dvd
    service: media_player.select_source
 - alias: 'Red Light On' 
   data:
      brightness: 100
      entity_id: light.wohnzimmer
      rgb_color:
      - 255
      - 0
      - 0
      transition: 50
    service: light.turn_on

My actual considerations:

  • ATM the Vero is always on, so sth. like “play sound when Vero/Kodi is turning on” would possible with some further effort

  • Playing a local MP3 via OSMC would turn on the local player, but I want to have the movie screen when projector is turned on

  • The only Add-On in this direction I know is CinemaVision, but I didnt found a fitting feature on a first view into it. Maybe there a others that could solve this…?

  • Within Home Assistant I could call a Kodi JSONRPC method, but I have no clue what this is

  • Utilizing an external player via AVR would involve a Zone 2 configuration, but this also seems like a complicated workaround

I hope I missed a simpler solution here, achieving this last step is my first milestone with HA.
Thanks
Kelvin