The album comprises 12 tracks, and 4 of them were initially composed for other artists, such as "A Key" for Shizuka Kudo and "Only for the Sake of Love" for Hiromi Iwasaki. "Say Goodbye to That Goodbye", a song originally recorded by Tomomi Kahala, became the final release for her who has semi-retired since 2007. The most well-known is "Ship in the Air" interpreted by boy band Tokio. Their recording was featured as the closing theme for My Boss, My Hero, a television drama remake of Korean motion picture and starring Tomoya Nagase, a lead vocalist of the band. It was released as a single in August 2007 and debuted at the number-one on the Japanese Oricon weekly singles chart with more than 120,000 copies sold.  A song remained on the country's hit parade for about a year, finally becoming one of the biggest hit singles for the group.
In December 2006, her successful contribution for Tokio was acclaimed by the Japan Composer's Association, winning the 48th Japan Record Award for "Best Lyrics".
Because "Ship in the Air" by Tokio became massive hit, Lullaby Singer also gained relatively moderate commercial success with the sales of 110,000 copies, despite it managed to enter the top-10 on the Oricon albums chart.
All songs written and composed by Miyuki Nakajima, arranged by Ichizo Seo (except M1/10 co-arranged by Nakajima, M7/11 co-arranged by Satoshi Nakamura, and M8/12 co-arranged by Nakajima and Ittetsu Gen)
"Sakura La La La La (桜らららら,Sakurarararara?)" – 2:24
"Only for the Sake of Love (ただ・愛のためにだけ,Tada Ai no Tame ni Dake?)" – 5:19