Between the release of his first album in 1962 and 2024, Marcos Valle has released twenty-two studio albums traversing definitive bossa nova, classic samba, iconic disco pop, psychedelic rock, nineties dance and orchestral music. With his twenty-third studio album Túnel Acustico, Valle set out to bring it all together. Originally moving over in the mid-sixties on the back of bossa nova's international proliferation, Valle toured with Sergio Mendes and became hugely in demand as a composer and arranger. He spent the years following Vietnam in Rio writing music for TV and film, as well as four cult favorite albums in collaboration with some of Brazil's most groundbreaking musicians including Milton Nascimento, Azymuth, Som Imaginario, and O Terco. Túnel Acústico features two songs originally conceived during Valle's time on the West Coast: "Feels So Good," a stirring two-step soul triumph written in 1979 with soul icon Leon Ware, and the sublime AOR disco track "Life Is What It Is," composed around the same time, with percussionist Laudir De Oliveira from the group Chicago. Built around an unfinished demo Marcos found on a shelf in his house 44 years after it was made, the "Feels So Good" demo was restored with the help of producer Daniel Maunick, who also utilized AI stem-separation to remove the placeholder vocal ad-libs. Valle added Portuguese lyrics to sit alongside Ware's vocal hook, as well as extra keyboards and percussion. On Túnel Acústico, Valle's core band features two members of the renowned Brazilian jazz-funk group Azymuth: Alex Malheiros on bass and Renato Massa on drums. The rhythm section is completed by percussionist Ian Moreira, with additional contributions from guitarist Paulinho Guitarra and trumpeter Jesse Sadoc. The contemporarily composed music on Túnel Acústico features an impressive lineup of guest lyricists, including renowned Brazilian artists: Joyce Moreno, Céu, and Moreno Veloso, as well as Valle's brother Paulo Sergio Valle.