Question: What ingredient do a Tom Collins and an Old Fashioned have in common?

Context articles: An Old Fashioned Love Song
Tom Collins (record producer)
I'm Old Fashioned (ballet)
Old Fashioned
American Trilogy Cocktail
Just an Old Fashioned Love Song
Such Is Life (novel)
Old Fashioned glass
Tom Collins
An Old Fashioned Thanksgiving

"An Old Fashioned Love Song" is a 1971 song written by Paul Williams and performed by the American pop-rock band Three Dog Night.
 Chuck Negron performed the lead vocal on this track.
 Taken as the lead single from their 1971 album, "Harmony", the song peaked at number four on the "Billboard" Hot 100 chart in December 1971, becoming the band's seventh top-ten hit.
 It was Three Dog Night's first record to top the U.S. easy listening chart.
 It reached number two in Canada.
 Its lyrics suggest the straightforward and melodic nature of the tune: "Just an old fashioned love song / Comin' down in three part harmony / Just an old fashioned love song / One I'm sure they wrote for you and me".
Tom Collins (born Bernie Tom Collins on May 30, 1942) is an American music producer and publisher in Nashville, Tennessee who has received three CMA Awards as Producer of the Year, and seven Grammy nominations.
 He produced a steady stream of country music hits over a 30-year span from artists including Ronnie Milsap, Barbara Mandrell, Sylvia, Tom T. Hall, Jim Ed Brown, James Galway, Marie Osmond, and Steve Wariner.
 Collins served as Chairman of the Board of the CMA in 1979 and 1980.
I'm Old Fashioned (The Astaire Variations) is a ballet made by New York City Ballet balletmaster Jerome Robbins to Morton Gould's adaptation of a theme by Jerome Kern, “I'm Old Fashioned,” to a Fred Astaire and Rita Hayworth sequence from the film "You Were Never Lovelier".
 The premiere took place on Thursday, June 16, 1983, at New York State Theater, Lincoln Center.
 It was titled "Variations on "I'm Old Fashioned"" at its first performance, but the name was truncated to its current form the following week.
The Old Fashioned is a cocktail made by muddling sugar with bitters, then adding alcohol, such as whiskey or brandy, and a twist of citrus rind.
 It is traditionally served in a short, round, tumbler-like glass, which is called an Old Fashioned glass, named after the drink.
The American Trilogy cocktail is a variation of the classic Old Fashioned.
 Barmen Richard Boccato and Michael McIlroy, created the American Trilogy in 2007 while bartending together at New York’s Little Branch.
 This Old Fashioned-style cocktail follows the same bitters, sugar, whiskey and orange peel profile as the classic, but uses orange bitters, a brown sugar cube and one part Applejack and one part rye whiskey to change it up.
 As the name implies, each ingredient of this three-part cocktail represents one pillar of the Trilogy.
 Laird’s Bonded Applejack Brandy is the first and oldest distilled spirit in America with American rye whiskey following soon after in the late 1700s.
 The third pillar of this cocktail is somewhat of a mystery according to creator Richard Boccato, but is often thought to be the orange bitters because of its American Origins.
Just an Old Fashioned Love Song is a studio album by Paul Williams, released in 1971.
 Notable songs, that were hits for other artists, on the album include "(Just An) Old Fashioned Love Song", "We've Only Just Begun", "Let Me Be the One" and "When I Was All Alone".
Such Is Life: Being Certain Extracts From The Diary of Tom Collins is a novel written by the Australian author Joseph Furphy (aka Tom Collins) in 1897, and published on 1 August 1903.
 It is a fictional account of the life of rural dwellers, including bullock drivers, squatters and itinerant travellers, in southern New South Wales and Victoria, during the 1880s.
The Old Fashioned glass or rocks glass is a short tumbler used for serving tan spirits, such as whisky, with ice cubes ("on the rocks").
 It is also normally used to serve certain cocktails, such as the Old Fashioned, from which it receives its name.
The Tom Collins is a Collins cocktail made from gin, lemon juice, sugar, and carbonated water.
 First memorialized in writing in 1876 by Jerry Thomas, "the father of American mixology", this "gin and sparkling lemonade" drink is typically served in a Collins glass over ice.
An Old Fashioned Thanksgiving is a television film based on a short story by Louisa May Alcott.
 Filmed on location in Canada, the film premiered on Hallmark Channel on November 22, 2008.
 It is followed by the sequel, "An Old Fashioned Christmas" which aired on December 11, 2010.