With their breakthrough song, 1965's "The Sound of Silence," and 1968's "Mrs. Robinson," from the soundtrack to "The Graduate," Simon & Garfunkel had already scored two Hot 100 No. 1 hits. But "Bridge Over Troubled Water" surpassed them both, topping the Hot 100 for six weeks in February, March and April 1970. It also was the title track of duo's swan song album, as the artists ended their continuous partnership with the Grammy-winning set. In 1974, Paul Simon brought the lushly arranged hit back to its gospel roots with a soulful version on his "Live Rhymin'" album performed with the Jessy Dixon Singers. --Thom Duffy

Before claiming a second No. 1 with "Joy to the World," Three Dog Night lead vocalists Danny Hutton, Cory Wells and Chuck Negron-using the moniker Redwood-left their mark on early recordings with Beach Boys guru Brian Wilson. The Los Angeles pop-rock group kicked into overdrive between 1969 and 1975, charting 21 pop hits including initial No. 1 "Mama Told Me (Not to Come)" in 1970. After disbanding in 1977, the group reunited in 1983 just as "Joy to the World" enjoyed renewed attention when it was featured on the soundtrack to Academy Award-nominated film "The Big Chill." With a current lineup that features founders Wells and Hutton, the group still performs a number of times each year. --Gail Mitchell

Roberta Flack was discovered by jazz musician Les McCann and signed to Atlantic and her first two albums were well-received, but they ultimately failed to produce any hit singles. That all changed when a version of Ewan MacColl's "The First Time Ever I Saw Your Face," from Flack's first album "First Take," was included on the soundtrack to the Clint Eastwood film "Play Misty for Me." The single zoomed to No. 1 in 1972 and remained there for six weeks. It was the top pop single for that year and won the Grammy for both record and song of the year. --Evie Nagy

In 1970, Tony Orlando was a retired singer of covers with a pair of top 30 hits in 1961 and one in 1969 (as lead for Wind). He was working as a publisher for Columbia Records, and upon discovering "Candida" in 1970, producer Hank Medress insisted he dub over the original track. To save face, Orlando decided to record the song as "Dawn." When it reached No. 3 on the Hot 100, the singer was willing to return as a marquee act with "Knock Three Times," which hit No. 1 for three weeks. Three years later, Tony Orlando & Dawn-featuring Motown/Stax backing vocalist Thelma Hopkins, Joyce Vincent Wilson and Vincent Wilson's sister Pamela Vincent-hit Hot 100 pay dirt with "Tie a Yellow Ribbon Round the Ole Oak Tree," which spent four weeks at No. 1 stateside and in the United Kingdom, seven weeks in Australia and earned a Grammy nod. Ultimately, it became the top-selling single and No. 1 song for 1973. --Chuck Taylor

Though Barbra Streisand scored her first Billboard chart single with 1964's "People" (from the musical "Funny Girl"), it wasn't until 10 years later that she had her first No. 1, "The Way We Were." The song, taken from the 1973 movie that starred Streisand and Robert Redford, was originally arranged in a sweeping orchestral style replete with harp accents. "The Way We Were" earned writers Marvin Hamlisch and Alan & Marilyn Bergman best song Academy Awards and song of the year Grammys, but it went to No. 1 only after it received a wah-wah-laden pop makeover on Streisand's studio album following the film. --Ayala Ben-Yehuda

As married couple Toni Tennille and Daryl Dragon worked to finish their debut album for A&M, a label A&R exec suggested they attempt Neil Sedaka's "Love Will Keep Us Together." The duo was looking for a song that could feature the Captain's keyboard skills, and after conjuring a new arrangement, all agreed that it sounded like a launch hit. "Love" debuted at No. 98 on April 19 and nine weeks later began its perch at No. 1 for four weeks. The song ultimately won the Grammy for record of the year. Almost five years later, the act reached No. 1 again on the Hot 100 with "Do That to Me One More Time." In all, Captain & Tennille scored nine top 40 hits between 1975 and 1980. --Chuck Taylor

Paul McCartney's response to criticism that his songs were lyrically and melodically fluffy was to release this bouncy piece of pop cotton candy as the lead single from the band's "Wings at the Speed of Sound" album. Quickly gaining favor at radio, the single debuted in April 1976 while Wings were in the midst of a world tour and began a five-week run at No. 1 in May in just its seventh chart week, eventually spending 19 weeks on the chart. --Ray Waddell

The seduction ballad from Rod Stewart's "Night on the Town" album caused a fair amount of controversy for its lyrics about the deflowering of a "virgin child," but nevertheless the single held sway on the Hot 100 for eight weeks beginning in the fall of 1976. The song, which spent 23 weeks on the chart, is also known for featuring romantic murmuring in French near the fade-out from actress Britt Ekland, Stewart's girlfriend at the time. --Ray Waddell

When the Bee Gees launched younger brother Andy Gibb in the midst of their hallowed disco days, he became the first debut solo artist in the history of the Hot 100 to score three consecutive No. 1s, with "I Just Want to Be Your Everything," "(Love Is) Thicker Than Water" and, in 1978, "Shadow Dancing"-the last of which spent seven weeks atop the chart. Gibb's astonishing run went on to include three more top 10s and a total of nine top 40 hits between 1977 and 1981. He also became one of the first tabloid mainstays, with romantic ties to Victoria Principal in the early '80s and the drama surrounding his sudden death in 1988 from alleged cocaine abuse. --Chuck Taylor

Long before the Plain White T's said "Hey There" to Delilah, the Knack penned this hit about a teenage crush. Lead singer Doug Fieger never managed to hook up with Sharona, but she did inspire him to write the No. 1 song of 1979, which stayed at the top of the chart for six weeks. Since it topped the Hot 100, the song has appeared in a number of movies, including "Reality Bites," and has been covered by everyone from Nirvana to Italian metal band Eldritch. In 2006, the band even filed suit against Run-D.M.C. for sampling the song in the rap act's 1986 single "It's Tricky." The band never replicated the success it had with "Sharona"; follow-up single "Good Girls Don't" peaked at No. 11. --Cortney Harding