The Singing Valentine goes like this: an acapella quartet dresses up in uniform, and drives from place to place singing for each sweetheart on their list, typically a wife, mother or intimate friend. They arrive at the appointed location, and look for the person receiving the SV. Since most of these are meant as surprises, this may mean checking in with an insider organizing the surprise, especially if it's a place of work. They walk in, often give the sweetheart a flower and declare that they have a message from the one who loves them. Then they sing a love song or two, take a photo, if requested to, and deliver any specific message the sender may want included. Here are some videos from the web showing singing valentines:
Off the Hook - typical barbershop SV delivery
Chelsea Parade - less talented, but lots of heart
Red Bank quartet - newscaster follows a SV quartet, showing how it touches lives
The program volunteers are members of the Barbershop Harmony Society, a fellowship of people who like to sing, or a sister group Sing United International. BHS is a grassroots organization, with most of the real activity occurring in the local chapters. The parent organizations sponsor conventions, contests and training programs, and provides services for the chapters like liability insurance, marketing and outreach.
In short, there is a small army of trained harmonic vocalists out there, the majority of whom respect and appreciate those who sacrifice years and burden risks to keep our country safe and free. These willing volunteers gladly step up to deliver these Singing Valentines to military families, in honor of their service.