Those who remember the Glen Echo Park of 20 years ago, the Spanish Ballroom with its Alhambraesque windows and the dancing that used to go on there have reason to take heart. The ballroom came alive again Saturday to the soft brass, swing sounds of The Band from Tin Pan Alley.

Couples, varying in age from 26 to 66, jitterbugged, fox-trotted and free-lanced through three hours of unqualified fun. The term "ballroom dancing" conjures up visions of formal attire and concentrated dance stepping, but this crowd was out for amusement in shirt sleeves.

Lending an international flair to the goings-on were James and Ruth Etchells, here on vacation from England. They echoed the enthusiasm of many of the dancers, remarking, "We're here for the sheer pleasure of it all, since you can't find many places to ballroom dance nowadays. Most every place is disco now."

During band breaks, dance teacher Pat Snyder gave group lessons in line dancing and some ballroom steps. As a veteran of the ballroom's days of glory, she shakes her head in disappointment that it has fallen into so much disrepair. No dancing can be scheduled in the heat of August or in the coldest months because there is neither air conditioning nor heating plant.

Across the massive floor Saturday night, girlfriends taught boyfriends, fathers danced with daughters and several National Park Service employes joined in the revelry. One young woman brought along her embroidery. She was no wallflower. She preferred to respectfully decline invitations and watch the dancers.

As the ballroom grew steamier, numerous couples went through gallons of ice water and sought relief outdoors at picnic tables beneath large trees -- within earshot of the band's music.

The local jazz band, which played popular dance tunes from the past five decades, had to break almost every half hour to cope with the heat. Band member Ed Fishel spoke highly of the ballroom's acoustics, suggesting, "It makes us sound a little like Glenn Miller's band." He too hoped that the ballroom would someday be able to provide year-round Saturday night dances. "Where else can anyone have so much fun for $2?"

Enough slow music was played to permit plenty of old-fashioned touch dancing. Some argued that this was the only type of music everyone could dance to.

The Saturday night dance series continues at Glen Echo with square dancing the rest of this month. Resuming in September, there will be more square dancing, waltzing and courtly dances of the Renaissance, all with live music. The dances start at 8:30 p.m. Details on future events are available at 229-5042.