The letter yer (Ъ, ъ, italics Ъ, ъ) of the Cyrillic script, also spelled jer or er, is known as the hard sign (твёрдый знак [ˈtvʲor.dɨj znak]) in the modern Russian and Rusyn alphabets and as er golyam (ер голям, "big er") in the Bulgarian alphabet. The letter is called back yer in the pre-reform Russian orthography, in Old Russian, and in Old Church Slavonic. Originally the yer denoted an ultra-short or reduced middle rounded vowel. Its companion is the front yer, now known as the soft sign in Russian and as er malək (ер малък, "small er") in Bulgarian (Ь, ь), which was originally also a reduced vowel, more frontal than the ъ, and which is today used to mark the palatalization of consonants in all of the Slavic languages written in the Cyrillic script, except for Serbian and Macedonian, where it is not used although its traces can be seen in the letters њ and љ. The two reduced vowels together are called the yers in Slavic philology.

In the Old Church Slavonic language, the yer was a vowel letter, indicating the so-called "reduced vowel": ъ = *[ŭ], ь = *[ĭ] in the conventional transcription. These vowels stemmed from the Proto-Balto-Slavic short */u/ and */i/ (compare Latin angulus and Old Church Slavonic ǫgъlъ. In all West Slavic languages the yer either disappeared or was transformed into /e/ in strong positions, and in South Slavic languages strong yer reflexes differ widely across dialects.

John Winston Ono Lennon, MBE (9 October 1940 – 8 December 1980) was an English musician and singer-songwriter who rose to worldwide fame as one of the founder members of The Beatles, one of the most commercially successful and critically acclaimed acts in the history of popular music. Together with Paul McCartney, he formed one of the most celebrated songwriting partnerships of the 20th century.

Born and raised in Liverpool, Lennon became involved as a teenager in the skiffle craze; his first band, The Quarrymen, evolved into The Beatles in 1960. As the group disintegrated towards the end of the decade, Lennon embarked on a solo career that produced the critically acclaimed albums John Lennon/Plastic Ono Band and Imagine, and iconic songs such as "Give Peace a Chance" and "Imagine". After his marriage to Yoko Ono in 1969, he changed his name to John Ono Lennon. Lennon disengaged himself from the music business in 1975 to devote time to raising his infant son Sean, but re-emerged with Ono in 1980 with the new album Double Fantasy. He was murdered three weeks after its release.

Thomas Earl "Tom" Petty (born October 20, 1950) is an American singer-songwriter and multi-instrumentalist. He is the frontman of Tom Petty and the Heartbreakers and was a founding member of the late 1980s supergroup Traveling Wilburys and Mudcrutch. He has also performed under the pseudonyms of Charlie T. Wilbury, Jr. and Muddy Wilbury.

He has recorded a number of hit singles with the Heartbreakers and as a solo artist, many of which remain heavily played on adult contemporary and classic rock radio. His music, and notably his hits, have become popular among younger generations as he continues to host sold-out shows. Throughout his career, Petty and his collaborators have sold 60 million albums.

Tom Petty was born and raised in Gainesville, Florida, and attended Gainesville High School. His interest in rock and roll music began at age 10 when he met Elvis Presley. In the summer of 1961, his uncle was working on the set of Presley's film Follow That Dream in nearby Ocala, Florida and invited Petty to come down and watch the shoot. He instantly became an Elvis Presley fan and soon traded his Wham-O slingshot for a box of Elvis 45s. In a 2006 interview on the National Public Radio program Fresh Air, Petty said that he knew he wanted to be in a band the moment he saw The Beatles on The Ed Sullivan Show. One of his first guitar teachers was Don Felder, a fellow Gainesville resident, who would later join the Eagles. As a young man, Petty worked briefly on the grounds crew for the University of Florida, but never attended as a student. An Ogeechee lime tree that he planted while employed at the University is now called the Tom Petty tree.