Low." Biographer Paul Trynka writes that the record evokes "both past and future". It also follows the same structure as its predecessor, with side one featuring more conventional tracks, and side two featuring mostly instrumental tracks. Author Peter Doggett writes that whereas Low featured lyrics of autobiographical nature, the lyrics of "Heroes" were "oblique and often deliberately evasive", and were sung with an "astonishing" amount of passion. Visconti recalled that lyrics were made up on the spot, with Bowie sometimes ad-libbing entire songs, singing "at the top of his lungs". Songs of this instance included "Joe the Lion", a tribute to American artist Chris Burden, who was known for his outlandish publicity stunts, and "Blackout", which references the New York City blackout of 1977. Like the second side of Low, the imagery of the Berlin Wall dominates "Heroes" throughout; a kiss between Visconti and Maass at the foot of the Wall inspired a lyric for the title track. Bowie's vocal for "Heroes" goes from calm and playful to a near-scream, a style he called "Bowie histrionics". Musically, Fripp's guitar feedback dominates throughout, while the bass pulsates and Eno synthesisers blends in the background. Bowie explained the song is about "facing reality and standing up to it" and finding joyness in life. Buckley particularly highlights the lyric "We can be heroes, just for one day" as "an acknowledgment that the future didn't belong to him anymore, [but] to everyone". "Sons of the Silent Age" was the only song written before the sessions began and was originally intended to be the album's title track. The lyrics are influenced by the works of Jacques Brel and follow several characters that are, in O'Leary's words, "part-homo superior/part-Bewlay Brothers". Musically, the song is noted by biographers as different than the rest of the songs on the album, in that the themes present reflect ideals from the previous decade rather than the contemporary, while O'Leary likens its sound more to that of Hunky Dory (1971) than the rest of the album. Biographers also consider the album's closer, "The Secret Life of Arabia", as a precursor to what Bowie would explore on Lodger. The instrumentals are described by Buckley as dark and gloomy. "Sense of Doubt" puts a repeating four-note piano motif against a set of synthesisers to paint an image of a barren landscape. Bowie plays the Japanese instrument koto on "Moss Garden" which, together with