Given the question: Information:  - A musician (or instrumentalist) is a person who plays a musical instrument or is musically talented. Anyone who composes, conducts, or performs music may also be referred to as a musician.   - Old Canes is a rock band from Lawrence, Kansas currently composed of front man Christopher Crisci (of The Appleseed Cast) on vocals and guitar, and a rotating cast of musicians. Because most of the band members, including Crisci, participate in other bands, Old Canes is joined on tour by other available musicians known to the band, including John Momberg (of The Appleseed Cast), Taylor Holenbeck, Sam Goodell, Rusty Scott, Kelly Hangauer (of Fourth Of July), Lucas Oswald (Minus Story) and Jeff Stolz, in what they call a "musical collective." Past members include Nathan Richardson (Casket Lottery), Jordan Geiger (Minus Story), Eric Verhar, Tyler French (Minus Story), Gabriel Booth, Kelsey Richardson, and Jon Anderson (Boys Life).  - Lucas Harrison Oswald ( born June 11 , 1988 ) is an American musician , known as a multi-instrumental and vocal contributor to the bands Shearwater , The Appleseed Cast , Minus Story , Hospital Ships , and Old Canes . He composed music for the second and third seasons of Green Porno and one episode of the American television show Boss ( TV series ) .  - Music is an art form and cultural activity whose medium is sound and silence, which exist in time. The common elements of music are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics (loudness and softness), and the sonic qualities of timbre and texture (which are sometimes termed the "color" of a musical sound). Different styles or types of music may emphasize, de-emphasize or omit some of these elements. Music is performed with a vast range of instruments and vocal techniques ranging from singing to rapping; there are solely instrumental pieces, solely vocal pieces (such as songs without instrumental accompaniment) and pieces that combine singing and instruments. The word derives from Greek  ("mousike"; "art of the Muses"). In its most general form, the activities describing music as an art form include the production of works of music (songs, tunes, symphonies, and so on), the criticism of music, the study of the history of music, and the aesthetic examination of music. Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound."    After reading the paragraphs above, we are interested in knowing the entity with which 'lucas oswald' exhibits the relationship of 'instrument'. Find the answer from the choices below.  Choices: - guitar  - singing
The answer is:
guitar