Some context: The Roots is an American hip hop band, formed in 1987 by Tariq "Black Thought" Trotter and Ahmir "Questlove" Thompson in Philadelphia, Pennsylvania, United States. The Roots are known for a jazzy and eclectic approach to hip-hop featuring live musical instruments. Malik B., Leonard "Hub" Hubbard, and Josh Abrams were added to the band (formerly named "The Square Roots"). Since its first independent album-length release the band has released 10 studio albums, two EPs, two collaboration albums (with other artists), and also collaborated on recordings and in live shows with a wide variety of artists in many musical genres.
The Roots originated in Philadelphia with Ahmir "Questlove" Thompson and Tariq "Black Thought" Trotter while they were both attending the Philadelphia High School for the Creative and Performing Arts. They would busk out on the street corners with Questlove playing bucket drums and Tariq rapping over his rhythms. Their first organized gig was a talent show in 1989 at the school where they used the name Radio Activity, which began a series of name changes that progressed through Black to the Future and then The Square Roots. In 1992, they dropped the "Square" because a local folk group had claim to the name.  Organix was the band's first album, released and sold independently in 1993. It drew offers from music labels, and the band signed with DGC/Geffen. The Roots' first album for DGC, Do You Want More?!!!??!, was released in 1994. It was a moderate hit among alternative music fans, boosted by the group's appearance at Lollapalooza. The band performed at the Montreux Jazz Festival that year. Touring guests, beatboxer Rahzel and producer Scott Storch, joined The Roots.  The 1996 release Illadelph Halflife was the group's first album to break the Top 40 on the Billboard 200 chart, spurred in part by MTV's airplay of the video for "What They Do" (a parody of rap video cliches) and "Clones", which was their first single to reach the top five on the rap charts. "What They Do" was also the group's first single to hit the Top 40 of Billboard's charts, reaching a peak of #34. While continuing on the path of live instrumentation, the album's sound was somewhat darker.
Who started it
A: Ahmir "Questlove" Thompson and Tariq "Black Thought" Trotter
Some context: Sonata Arctica is a Finnish power metal band from the town of Kemi, Finland. Created as a hard rock band named Tricky Beans, they later changed to Tricky Means and finally to Sonata Arctica, when they shifted to power metal. The current line-up consists of singer, keyboardist and songwriter Tony Kakko, guitarist Elias Viljanen, bass guitarist Pasi Kauppinen, keyboardist and keytarist Henrik Klingenberg, and drummer Tommy Portimo. All the musicians of the band's history except Portimo also acted as backing vocalists.
The band was founded by Marko Paasikoski (guitar), Jani Liimatainen (guitar) and Tommy Portimo (drums) in Kemi at the end of 1995 (Tony Kakko (vocals) and Pentti Peura (bass) joined in early 1996). Originally named Tricky Beans, they played hard rock rather than the power metal with which they grew to fame. Kakko explained that when he was invited to join the band, Paasikoski said the band was going to play "a mixture of Megadeth and Spin Doctors". During their early career, they recorded three demos which were never sent to a recording label -- Friend 'til the End, Agre Pamppers and PeaceMaker. According to Kakko, the band's first name was based on one of their early songs, which was "about a lady who was tricky and I didn't really know what I was talking about (laughs)". Their first show was about to take place but they were still unnamed, so they had to come up with something.  In 1997 the band changed their name to Tricky Means, and from that point until 1999 their style was thoroughly worked upon and ultimately was drastically changed, acquiring a strong emphasis on the keyboard melodies and relying on an easily distinguishable rhythm line maintained both by the bass and the guitar. Vocalist Tony Kakko developed a clean singing style which relies both on falsetto and tenor voices. Kakko has stated that the change of sound was influenced by fellow Finnish power metal band Stratovarius. At that time, Pentti Peura was fired and Marko Paasikoski left due to a lack of gigging. Two months later the band got signed to a three-album deal with Spinefarm, which left Marko displeased. The band finally changed their name to Sonata Arctica, because they thought they wouldn't be able to sell metal albums with the previous name and also because Spinefarm asked them to do so. "Sonata Arctica" was suggested by a friend of the band: "sonata" for the music and "arctica" for their home (Kemi, in Northern Finland).  In 1997, they recorded a demo entitled FullMoon in Kemi's Tico Tico Studios, which was their first real metal recording. The line-up consisted of vocalist and keyboardist Tony Kakko, guitarist Jani Liimatainen, new bassist Janne Kivilahti (who started first as second guitarist) and drummer Tommy Portimo. The demo was sent to Spinefarm Records by a friend of the band and a recording deal soon followed.
Did they know each other previously?
A:
Originally named Tricky Beans, they played hard rock rather than the power metal with which they grew to fame.