I asked the question of Delta's customer care via e-mail a few weeks back, and received the response below. They made it sound as though Song is a separate entity from Delta:
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Hello John,
Thanks for getting in touch with Song.
Delta courtesy coupons are only valid on Delta flights.
We look forward to seeing you on Song!
Joanna,
Song Guest Services
www.flysong.com
All Song flights are operated by Delta Air Lines
Original Message Follows:
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PERSONAL INFORMATION:
Name : Mr John Haglund
Email Address :
[email protected]
SkyMiles Number:
COMMENT DETAILS:
Email about Past/Future travel: Current and Future
Nature of Comment: Question Suggestion
Email Pertaining to: Onboard_Aircraft
Email about Other topic:
Comments:
Hi, are Delta courtesy coupons (headset, cocktail, etc.) good for use on
Song flights?
Thanks,
John