Question: What is the profession of the American who sings in the lowest vocal range? 

Context paragraphs:
Alto: The musical term alto, meaning "high" in (Latin: ), refers to the second highest part of a contrapuntal musical texture and is also applied to its associated vocal range, especially in choral music.  It is also the root word of contralto, the lowest standard female voice type.  When designating instruments, "alto" likewise can refer either to the corresponding vocal range (alto flute and alto trombone) or to musical role (alto recorder and alto clarinet).

Georgia Brown (Brazilian singer): Georgia Brown, pseudonym of Rossana Monti (born June 29, 1980) is an Italian Brazilian singer noted for her extensive vocal range.  She was listed in the 2005 "Guinness World Records" for hitting the highest vocal note and for possessing the greatest vocal range for a female, claimed to be exactly eight octaves from G-G using scientific pitch notation.  However, as of 2013, Tim Storms holds the record for the widest vocal range of any human with 10 octaves.

Basso profondo: Basso profondo (Italian: "deep bass"), sometimes basso profundo or contrabass, is the bass voice subtype with the lowest vocal range.

List of basses in non-classical music: The bass singing voice has a vocal range that lies around the second E below middle C to the E above middle C (i.e., E–E).  As with the contralto singing voice being the rarest female voice type, the bass voice is the rarest for males, and has the lowest vocal range of all voice types.  However, the bass voice is determined not only by its vocal range, but also by its timbre, which tends to be darker than that of a baritone voice.

Bass (voice type): A bass ( ) is a type of classical male singing voice and has the lowest vocal range of all voice types.  According to "The New Grove Dictionary of Opera", a bass is typically classified as having a vocal range extending from around the second E below middle C to the E above middle C (i.e., E–E).  Its tessitura, or comfortable range, is normally defined by the outermost lines of the bass clef.  Categories of bass voices vary according to national style and classification system.  Italians favour subdividing basses into the "basso cantante" (singing bass), "basso buffo" ("funny" bass), or the dramatic "basso profondo" (low bass).  The American system identifies the bass-baritone, comic bass, lyric bass, and dramatic bass.  The German "fach" system offers further distinctions: Spielbass (Bassbuffo), Schwerer Spielbass (Schwerer Bassbuffo), Charakterbass (Bassbariton), and Seriöser Bass.  These classification systems can overlap.  Rare is the performer who embodies a single "fach" without also touching repertoire from another category.

Vocal fry register: The vocal fry register (also known as pulse register, laryngealization, pulse phonation, creak, croak, popcorning, glottal fry, glottal rattle, glottal scrape, or strohbass) is the lowest vocal register and is produced through a loose glottal closure which will permit air to bubble through slowly with a popping or rattling sound of a very low frequency.  During this phonation, the arytenoid cartilages in the larynx are drawn together which causes the vocal folds to compress rather tightly and become relatively slack and compact.  This process forms a large and irregularly vibrating mass within the vocal folds that produces the characteristic low popping or rattling sound when air passes through the glottal closure.  The register (if well controlled) can extend far below the modal voice register, in some cases up to 8 octaves lower, such as in the case of Tim Storms who holds the world record for lowest frequency note ever produced by a human, a G−7, which is only 0.189 Hz.  Humans however can only hear sounds down to 12 Hz under ideal conditions.

Range (music): In music, the range of a musical instrument is the distance from the lowest to the highest pitch it can play.  For a singing voice, the equivalent is "vocal range".  The range of a musical part is the distance between its lowest and highest note.

List of contraltos in non-classical music: The contralto singing voice has a vocal range that lies between the F below "middle C" (F) to two Fs above middle C (F) and is the lowest type of female voice.  In the lower and upper extremes, some contralto voices can sing from two Bs below middle C (B) to two B♭ s above middle C (B♭ ).  Although both men and women may have voices in the contralto vocal range, the word is usually used only in the context of a female singer.

Vocal fold nodule: Vocal fold nodules are bilaterally symmetrical benign white masses that form at the midpoint of the vocal folds.  Although diagnosis involves a physical examination of the head and neck, as well as perceptual voice measures, visualization of the vocal nodules via laryngeal endoscopy remains the primary diagnostic method.  Vocal fold nodules interfere with the vibratory characteristics of the vocal folds by increasing the mass of the vocal folds and changing the configuration of the vocal fold closure pattern.  Due to these changes, the quality of the voice may be affected.  As such, the major perceptual signs of vocal fold nodules include vocal hoarseness and breathiness.  Other common symptoms include vocal fatigue, soreness or pain lateral to the larynx, and reduced frequency and intensity range.  Airflow levels during speech may also be increased.  Vocal fold nodules are thought to be the result of vocal fold tissue trauma caused by excessive mechanical stress, including repeated or chronic vocal overuse, abuse, or misuse.  Predisposing factors include profession, gender, dehydration, respiratory infection, and other inflammatory factors.

Putnam Griswold: Putnam Griswold (1875–1914) was an American opera singer (bass), born in Minneapolis, Minnesota.  Originally he followed a business career.  At the age of 22 he discovered his voice and began to study with a local teacher in California.

Supporting paragraphs: Putnam Griswold Bass (voice type)
Answer: opera singer