Random close pack crystal lattices have maximum densities equal to this upper limit. Random close packing does not have a precise geometric definition. It is defined statistically, and results are empirical. A container is randomly filled with objects, and then the container is shaken or tapped until the objects do not compact any further, at this point the packing state is RCP. The definition of packing fraction can be given as: "the volume taken by number of particles in a given space of volume". In other words, packing fraction defines the packing density. It has been shown that the filling fraction increases with
Things Ain't What They Used to Be Be", "Blue Serge" and "Moon Mist". Jazz musician and historian Chris Tyle argues that most likely Mercer Ellington came up with the melody and his father then arranged the song for the band. The song is most often played as an instrumental. Lyrics were written by Ted Persons. Johnny Hodges played it first, in Hollywood on July 3, 1941. Duke Ellington played it for the film "Cabin in the Sky" (1943). Things Ain't What They Used to Be "Things Ain't What They Used to Be" is a 1942 jazz standard with music by Mercer Ellington and lyrics by Ted Persons.