Gordon Lightfoot wasn’t fooling around when he coined the name for his current tour: “50 Years On The Carefree Highway.” After entertaining an appreciative crowd Saturday night in the South Shore Room at Harrah’s Lake Tahoe, Lightfoot, 76, had logged eight concerts in 10 days. The Canadian-born singer-songwriter set the standard for folk/rock artists in the ‘60s and ‘70s, cranking out tunes such as “Carefree Highway,” “If You Could Read My Mind,” “Sundown” and “The Wreck of the Edmund Fitzgerald.” He’s been on the road ever since, delighting rainy-day people and fair-weather fans alike.