Here is an interesting case: a composer who had to make a living as a factory worker for a a few years.
Karl Gleitz (1862-1920) was born in Hitzerode near Kassel, Germany. He had his first musical training at the Leipzig Conservatoire and in Berlin. From 1882, he studied in Munich, with Rheinberger, with whom he did not get on. According to his autobiography, he was dismissed for insubordination. In 1893 the "Berliner philharmonische Orchester" played a concert with his compositions, conducted by Gleitz himself. Having financed that concert out of his own pocket, he was then forced to take on a job as a simple factory worker to make ends meet.
For a young composer with little money there was no way out than to teach, but this often meant teaching talentless pupils who paid very little, left to him by established teachers of renown. And to this he preferred physical labour.
In 1898/99 Nikisch performed Gleitz' Symphonic Poem 'Fata Morgana' at the 'Philharmonie' in Berlin, and in 1908 concerts took place in Hamburg with the following works:
1. Lieder for four-part female choir by W. Berger
2. Symphonia Masonica for large orchestra by K. Gleitz
3. Pietà. Wiegenlied. In Schlaf und Traum - by K. Gleitz
4. Te Deum by A. Bruckner
Gleitz' autobiography 'Künstlers Erdenwallen' (https://web.tresorit.com/l/7D6Ml#fhEyHlXz-DHoBO6swL01zg) (an artist's earthly travels), published in two slim volumes in 1896, makes for fascinating reading. It also contains some of his music, for example '10 Variationen für Pianoforte' (https://web.tresorit.com/l/1UMRA#NXDc8C5rEl-RWhWFgEy94w).
His 'Irrlichter' (Will-o'-the-wisp), Fantasy for piano and orchestra, op. 9, 1895, is held by the Staatsbibliothek Berlin and also in Cologne.
For anyone with enough cash (and interest), a 13 page handwritten treatise entitled 'Richard Strauß und der Symbolismus' is currently available from Kotte Autographs (https://www.kotte-autographs.com/en/autograph/gleitz-karl/#935330).
Some additional information:
For one of the Hamburg concerts that I mentioned, on 13 November 1908, his daughter, Martha Gleitz, barely 15 years old, is listed among the performers as a dancer. Her father had written 'In Schlaf und Traum' specially to feature her dancing.
The biographical entry in "Deutsche Tonkünstler und Musiker in Wort und Bild" by Friedrich Jansa, second edition, 1911, has this about Gleitz' use of dance in his compositions:
The dancing of his daughter, Martha, who studied with Isadora Duncan, gives his artistic work a special direction. He sees dance as a new instrument, another means of increasing expressiveness and clarifying the main idea of the work, and uses dance where the main character is expected to appear in the course of the work..
His symphonic poem 'Venus and Bellona', op. 10 was inspired by this painting (https://www.deutsche-digitale-bibliothek.de/item/BJJDAXDIDK445WEFR7ZS5SQLIA3TSTUC?query=%22Karl+Gleitz%22&isThumbnailFiltered=true&rows=20&offset=0&viewType=list&hitNumber=01) by Paul Schobelt (1838-1893).
Wikipedia (in German) has this works list (selection):
Sechs Charakterstücke für Klavier op. 1
Zwölf Lieder für Singstimme und Klavier op. 2
Sonate A-Dur für Violine und Klavier op. 3
Zwei Morceau für Orgel op. 6
Irrlichter. Fantasie für Klavier und Orchester op. 9
Venus und Bellona. Symphonische Dichtung für großes Orchester op. 10
Ein musikalischer Scherz. 9 Variationen über das Thema eines Laien für Klavier op. 11
Acht Lieder für Singstimme und Klavier op. 12
Joss Fritz. Symphonische Dichtung für großes Orchester op. 13
Vier Mädchenlieder für Mezzosopran und Klavier op. 14
Vier kleine Fantasiestücke für Klavier op. 15
Vier Lieder für mittlere Stimme und Klavier op. 20
Beim Wein. Fünf Lieder für Bariton und Klavier op. 21
Zwei Lieder für mittlere Stimme und Klavier op. 22
Fünf Salonstücke für Klavier op. 25
Vier Klavierstücke op. 26
Vier Lieder für Mezzosopran und Klavier op. 27
Vier Lieder für Singstimme und Klavier op. 28
Drei Klavierstücke op. 29
Hafbur und Signild für Soli, Chor und Orchester op. 34
Ahasver. Symphonische Dichtung für großes Orchester
Alberichs Drohung. Symphonische Dichtung für großes Orchester
Fata Morgana. Symphonische Dichtung für großes Orchester
Frühlings Erwachen. Symphonische Dichtung für großes Orchester
Simson. Symphonische Dichtung für großes Orchester
https://de.wikipedia.org/wiki/Karl_Gleitz
In the work list in "Künstlers Erdenwallen" (1896) five works with opus numbers are listed, with a note saying that they will be published later as the composer wants to make some changes. There were obviously some changes made to opus numbers, and it's not certain that the violin concerto was ever published.
Op. 4. Concert für Violine und Orchester.
Op. 5. Intermezzo für Orchester.
Op. 6. Alberichs Drohung.
Op. 7. Frühlings Erwachen.
Op. 8. Ahasver.
Op. 16 n° 3. Pietà für kleines Orchester
Not the same C.A. Gleitz whose 2 preludes and fugues were published in 1868 by Körner unless this fellow was a serious prodigy. HMB-up-to-1900 does list 27-odd works of his, in fact... SBB has several works of his as well including several in that list and some by the elder Karl Anton Gleitz who was alive in 1868 (the 2 preludes and fugues) too.
They have also Karl Gleitz's 4 Lieder Op.30 (pub.1898), 2 Tänze for piano Op.40 (pub.1902), e.g.
Free Library of Pennsylvania has the score (but not parts) of Irrlichter. They give the orchestration as "so-pn, 1-fl, 1-pc, 2-ob, 2-cl, 2-bn, 2-hn, 2-tpt, 1-trb, prc, str.", dedicated to Martha Siebold.
IMSLP does have his Opp.26&42.
In 'Collections With', there is one listing, a Postludien-Buch under his name that includes a 'Fuge in C-Dur', but this must be another Gleitz (dates: 1795-1879). This should not be under the same name, but I don't think I can change that.
I have asked at SBB for a digitalisation of Irrlichter.
Well, one can create a composer category for the other Gleitz (whose full name was Carl Anton Gleitz) and then in the CollCat section at the bottom of the Postludien-Buch page add Anton after Carl or Karl). I can do that later...