Question: Are Dickie Peterson and Fher Olvera both musicians?

full_context: Document 1: Dave Peters: Dave Peters is an American musician. He was the original guitarist for the band Eighteen Visions, guitarist for the band Throwdown, and, as of 2002, the vocalist for Throwdown. He did guest vocals for the song "Unleash" by groove metal band Soulfly, for the song "Feel as Though You Could" by Demon Hunter, and the song "Despair" for Living Sacrifice. He is straight edge.
Document 2: Lo Esencial de Maná: Lo Essential de Maná is a three CD box set of the first three studio albums under recording label WEA Latina from Mexican rock band Maná. Since they burst on the scene from Guadalajara, Mexico, in the early 1990s, Maná have reigned as the premier Latin rock band of our time. Led by the powerful and passionate vocalist-composer Fher Olvera, drummer Alex González, guitarist Sergio Vallín, and bassist Juan Diego Calleros blend American power rock with Hispanic folk idioms and Afro-Caribbean rhythms. This three-CD box set compilation contains the band's greatest hits, from their début album, "Falta Amor" to their third album "Cuando Los Ángeles Lloran". A total of 37 songs from their favorites appear, including "Vivir Sin Aire," "Dónde Jugarán los Niños?", and the reggae-tinged "Selva Negra." Other favorites, such as "La Chula" and "Como Te Deseo," are remixed as pop-dance numbers.
Document 3: Luis Miguel: Luis Miguel Gallego Basteri (born April 19, 1970) is a Mexican singer and an icon in Latin America, he is often referred to as "El Sol de México" (The Sun of Mexico). He is one of the most successful artists in Latin American history, having successfully performed in a wide range of musical styles, including pop, ballads, boleros and mariachi. To date, he has sold over 100 million records worldwide.
Document 4: Vicente Fernández: Vicente "Chente" Fernández Gómez (born 17 February 1940) is a Mexican retired singer, actor, and film producer. Nicknamed "El Rey de la Música Ranchera" (The King of Ranchera Music), Fernández started his career singing for tips on the street, and has since become a cultural icon, recording more than 50 albums and contributing to more than 30 films. His repertoire consists of rancheras and other Mexican classics. He is accompanied live by a mariachi group, but he is not technically a mariachi musician, as he plays no instrument live. Vicente's fame rose after the death of Javier Solis (El Rey del Bolero Ranchero). Vicente was inspired during many of his performances, by his long time friend Celso Baez.
Document 5: Dickie Peterson: Richard Allan Peterson (September 12, 1946 – October 12, 2009) was an American musician, best known as the bassist and lead singer for Blue Cheer. He also recorded two solo albums: "Child of the Darkness" and "Tramp".
Document 6: Fher Olvera: José Fernando Emilio "Fher" Olvera Sierra, was born in December 8, 1959, (Guadalajara, Jalisco, Mexico). He is the secondary guitarist, composer, and lead singer for the Mexican rock band Maná, the most successful Latin American band of all time with over 40 million albums sold worldwide.
Document 7: The Beast Is Back: The Beast Is Back is the seventh album by a newly reformed Blue Cheer, 13 years after their previous album, "Oh! Pleasant Hope" (1971). It contains re-recorded versions of some of the band's most popular songs from their late-1960s heyday as well as new material. The album features founding members Dickie Peterson and Paul Whaley. Original guitarist Leigh Stephens did not participate in the reunion.
Document 8: Oh! Pleasant Hope: Oh! Pleasant Hope is the sixth, and last, album by Blue Cheer until 1983's "The Beast Is Back". It features less psychedelia and hard rock and includes more folk rock elements. This is an unusual Blue Cheer album in that Dickie Peterson only sings lead on three songs. Another unusual aspect is that the song "I'm the Light" features extensive use of the sitar and synthesizer, although on the previous album "The Original Human Being" the song "Babaji (Twilight Raga)" also featured extensive use of the aforementioned instruments.
Document 9: Eric Peterson (musician): Eric Peterson (born May 14, 1964) is an American guitarist. He is best known as the only constant member of the US thrash metal band Testament. Peterson has also formed a side project black metal band called Dragonlord, in which he plays guitar and also sings. In Testament, Peterson was originally a rhythm guitarist while Alex Skolnick handled all lead work. More recently though, Peterson plays leads along with Skolnick.
Document 10: Maná en Vivo: Maná en Vivo (in English: Maná Live) is the first live album (and seventh overall) released by the Mexican rock band Maná. After Iván González and César López left the group, Fher Olvera, Alex González, and Juan Calleros continued to perform as a trio. They recorded "Maná en Vivo" in August and September 1994 during their ¿Dónde Jugarán Los Niños? World Tour. The double CD includes material from concerts at the Universal Amphitheatre in Los Angeles; the Sports Arena in San Diego; the Aragon Ballroom in Chicago; the Teatro Gran Rex in Buenos Aires, Argentina; the Estadio de Chile in Santiago, Chile; and the Sala Estandard in Barcelona, Spain. Olvera, González, and Calleros were joined by Carlos Orozco on guitar, Sheila Ríos on vocals, and Juan Carlos Toribio on keyboards.
Document 11: Peter Cetera: Peter Paul Cetera ( ; born September 13, 1944) is an American singer, songwriter, and bassist best known for being an original member of the rock band Chicago (1967–1985), before launching a successful solo career. His career as a recording artist encompasses seventeen albums with Chicago and eight solo albums.
Document 12: La Barranca: La Barranca has been a successful ongoing outfit for over a decade. Based in Mexico City, they are led by guitarist and songwriter José Manuel Aguilera, who previously and concurrently worked with Sangre Azteka, Jaguares, Cecilia Toussaint, Steven Brown/Nine Rain (Tuxedomoon), and more. He has an unusually economical style of playing that concentrates on great rhythms, superb tone, and very melodic solos. After the original lineup—Aguilera, Federico Fong (bass), Alfonso Andre (drums), all of whom were guest members of Jaguares with former Caifanes frontman Saúl Hernández—went its separate ways, a second version of the band included Santa Sabina guitar virtuoso Alex Otaola and the extremely flexible rhythm section of brothers Jose María ("Chema") and Alonso Arreola. The band's sound effortlessly moves from flat out rock to fusion-ish jamming and passes through a kind of Mexican folk influence along the way. Aguilera is a good singer with a talent for finding simple melodies amidst rather complex songs. On "El Fluir" the band decided to record live and to cut back on the keyboard and programmed additions to their music. Surprisingly, the result was not an over-the-top jamfest but rather a very tightly arranged set of songs that hinted at the overwhelming power they could possess in concert. The two guitar interplay between Aguilera and Otaola was highly impressive as they explored all forms of playing together and against one another (with Otaola pulling all sorts of radical sounds out of his guitar). "El Fluir" was their first US release since "Tempestad" in 1998. This edition was further sweetened by the inclusion of a previously unreleased bonus track and a video for the first single "Pare de Sufrir."
Document 13: Maná: Maná (Spanish: "manna") is a Mexican Rock music band from Guadalajara, Jalisco. The group's current line-up consists of vocalist/guitarist Fher Olvera, drummer Alex González, guitarist Sergio Vallín, and bassist Juan Calleros. Maná has earned four Grammy Awards, eight Latin Grammy Awards, five MTV Video Music Awards Latin America, six Premios Juventud awards, nineteen Billboard Latin Music Awards and fifteen Premios Lo Nuestro awards. It is considered by many as the most influential and successful Latin American band of all time with over 40 million albums sold worldwide.
Document 14: Pete Loeffler: Pete Loeffler (born October 19, 1976) is a musician, known for his work with the Chicago-area rock band Chevelle, for which he is the lead vocalist and sole guitar player.
Document 15: Pete Best: Randolph Peter "Pete" Best (born Randolph Peter Scanland, 24 November 1941) is an English musician, principally known as an original member and first drummer of the Beatles, from 1960 to 1962. He has been referred to as the Fifth Beatle.
ground_truth: yes