Heads turn. People stop to listen. Almost invariably, they dig into their purse or pocket and slip what they can into the red kettle next to Matthew Hall and his silver E-flat tuba.

Its a scene the 20-year-old Salvation Army volunteer has witnessed hundreds of times this holiday season, each one quite by design.

The most common thing I hear is that it sounds way better than the bells, said Hall, who spent most of his Saturday outside Keils market in San Carlos playing tuba and soliciting donations for charity.

One lady wrote me a check because my music stopped her, he said after a slow soulful rendition of O Come All Ye Faithful.

This holiday season, as so many struggle still to meet obligations and provide for their families, donations to the familiar red kettles have plunged by double digits.

Salvation Army officials say donations have dropped 15 percent or more nationally so far this year. They are crossing their fingers for a huge finish before Christmas morning.

Thanksgiving was so late this year, it just knocked five or six days off our schedule, said Adrienne Finley, who oversees fundraising for the Sierra Del Mar division, which includes San Diego, Imperial, Riverside and San Bernardino counties. We kind of lost a week.

The Red Kettle campaign is best known for the nonstop bell-ringing performed by armies of volunteers camped outside stores across the nation. The 150 volunteers deployed in San Diego County are critical to providing recovery, health, emergency and other services all year.

Money raised in San Diego stays in San Diego, Finley said.

Donations in some communities have dropped 30 or 40 percent over last year, the Salvation Army said.

Read more:

Tuba-playing volunteer charms red kettle donors