THE MARIPOSA Folk Festival opened its sixth season out at Innis Lake last night - musically ragged but with its skirts clean.

"We haven't missed a year," emcee folksinger Ian Tyson told the estimated crowd of 2,500. "We're not the oldest of all the festivals, but we're right up there with the old timers."

The five hours of concert that followed gave a new-penny-feel to Mariposa which has survived a beer-soaked past, post midnight rumbles through Orillia's main streets and hundreds of arrests for under age drinking.

Last night was a quiet Mariposa, and its organizers hope it will continue for the next two days.

A polite, attentive audience affectionately cheered honey-voiced singer Joni Mitchell, a former Torontonian, who regaled them with her own numbers, all with a Saskatchewan drifting theme.

They shouted for more from the traditional Beers Family, Bob, Evelyne and Martha, who alternated on the psaltry, fiddle, straws and guitar.

And they drenched this Festival's blockbuster name attraction Pete Seeger in a bath of tumultuous enthusiasm.

Ontario Provincial Police had a total of 103 officers posted at the entrance route and on the grounds, arrested "a very small number, maybe five or so" for liquor offenses.

Those that stayed to camp on the 100-acre Caledon East site had to pass through four OPP checkpoints before bedding down for the night. The campers waived LCBO rights which would give them permission to have liquor in their tents.

"If we survive the teeny boppers tonight we'll be all right," commented Festival program advisor Randy Ferris.

Actually, the teeny boppers, young female teenagers who scream, push and mob, were there last night along with grandmothers, grandfathers, mothers with infants in their arms, beards and longhairs.

But there wasn't much to scream for.

For example:

The Canadian Indian Dancers: A mixture of authentic Indian dances and white-man Indian "jokes" by Vic Pelletier that abetted the rigid stereotype and introductions such as: "You'll see this dance done as it was long before your ancestors came to this country."

The New Lost City Ramblers: Only one number that came over as the act opened the program and that was Parlez-Vous Avoir sung in Cajen but preceded by too much bramble-toned singing. The group failed to catch fire.

By the time cheering was in order it was well into the fourth straight hour.

Following Joni Mitchell the Chicago blues group of Sunnyland Slim, Big Walter Horton and Johnny Young with Andy Cree was pressed for time and could have gone on playing funky for hours.

But Seeger was to come on and come on he did with a bounce, whimsy, singalongs, historical notes and a chunk of anti-war, anti-Vietnam material.

Beginning at 1.01 a.m. he went through to 1.45, the latter final moments with an extended version of Down By The Riverside. The Staples Singers who are to perform tonight came on for several choruses and Mariposa '66 was officially launched into its second day.

"I learn so much by coming here and that's why I came," Seeger said. He and the other performers are working for a flat $40 to help Mariposa develop folk research projects during the year.

"It was the best opening night audience of any Mariposa yet," Tyson said later.