 "Ghost" incorporates styles from several musical genres, whereas her earlier works more prominently incorporated electropop styles.Writing for "Now", Kevin Ritchie felt that the project "suggests a much broader range of intriguing possibilities [...] for her dusky voice" than her previous music allowed, further suggesting that her earlier tracks "One" and "Obsession" saw Ferreira "succumbing" to the requests of her record label.Its opening track "Sad Dream" integrates acoustic guitar instrumentation; Joe Marvilli from No Ripcord stated that Ferreira's vocals "almost [cracked] out of sadness" during the chorus, adding that the lyrics "Hope the guilt will dim and fade / A fire baptism engulfs my shame" emphasize her discouragement.