Although some communities suggest that "any art by a Mando is Mando art," this sentiment is too broad to be useful as a way of defining the particular feel of "art of the Mandalorians." Rather, art of the Mandalorians incorporates at least one of a number of iconic symbols or themes. While the medium and style of such art is very different, key features make "art of the Mandalorians" immediately recognizable as such.
Stories and poems are written in Mando'a or focused on Mandalorians (but not writing that merely has Mandalorians in support roles) or aspects of the Mandalorian culture.
Visual art that is identifiable as distinctly Mandalorian has a few common elements. It prominently features at least one of the following: some variation of the beskar'ta (the chest diamond), the T-visor helmet, the kyrbes (mythosaur skull), jaig eyes, clan symbols, and any version the Mando'a script. Creating, decorating, and accessorizing beskar'gam (especially buyce, helmets) is common, both in sketches and cosplay.
Most music is either remakes of the music from the Republic Commando soundtrack, original work done in a combination of Mando'a and another language, or translations of existing work into Mando'a but set to the tune of the original piece.
This clip shows how some fans envision a marching drum for Mandalorians would look like: https://youtube.com/clip/UgkxqlyS_ykNLaPoIY8z38kfGmP4iejAnxd7?si=jqPjJmDOsxqh6pbU
Aside from mention of Mandalorians including symbols and personalizing the paint schemes of their armor, very little is known about the style of art from Legends material.
Meanings for color on armor mentioned in the novels (Legacy of the Force: Revelation, Order 66: A Republic Commando Novel, and Imperial Commando: 501st); lists with fan additions are left for individuals to find:
black: justice
blue: reliability
gold: vengeance
gray: mourning a lost love
green: duty
orange: a lust for life
red: honoring a parent
Examples of Mandalorian visual art from Disney canon
Official featurette about the art in The Mandalore Plot: https://www.youtube.com/watch?v=QrACnc_T5bQ
https://www.starwarsgeekgirl.com/post-1/highlighting-some-of-sabine-s-best-artwork
https://www.starwars.com/news/5-inspirational-works-of-art-from-sabine-wren
Mandlorian artists Tojnun and other unnamed Pre-Exile Masters influenced the work of Sabine Wren: https://starwars.fandom.com/wiki/Tojnun, https://starwars.fandom.com/wiki/Pre-Exile_Masters
Sabine Wren's art work can be found in this book: https://starwars.fandom.com/wiki/Sabine_My_Rebel_Sketchbook
And here is a sample of the pages: https://www.reddit.com/r/starwarsrebels/comments/hesczq/heres_some_pages_from_sabines_journalsketchbook/
This article has some screen captures of art from the television series, including some details about what the art is based on: https://starwarsmaven.info/appreciating-mandalorian-art/
Music analysis from real-world perspective: https://www.youtube.com/shorts/WrP6aEZwSAw
Jesse Harlin, Gamespot "SW RepCom Designer Diary 5" (February 14, 2005): As the final bit of polish, I created the ancient Mandalorian language specifically for Republic Commando. The Clones' ancestral language is largely inspired by a mix of Hungarian, Celtic war poetry, and Soviet proletariat work anthems.
Interview with Jesse Harlin about composing the Republic Commando soundtrack (including references to Mando'a): https://web.archive.org/web/20060615193250/http://musiconfilm.net/get_feature.php?id=6
Quote from Karen Traviss about Mando musical preferences:
https://boards.theforce.net/threads/mandoa-class-mandalorian-language.21531491/page-6#post-21556552
Mandalorian_Crusader: "Karen, would the Mandalorians have any preference in picking musical instruments or is all their music vocal?" Karen Traviss: "Overwhelmingly vocal. Occasional use of a dead thing's horn, hence the didgeridoo sound. They haven't got the space to carry round a brass band." Later, Karen Traviss added: "Don't confuse the soundtrack with what they actually have - because there's a whole orchestra in there. (There is no such thing as the Mandalore Philharmonic.) No, they don't have drums or flutes."
Republic Commando soundtrack that was once available on official Republic Commando website (archived backup): https://archive.org/details/RepublicCommandoOST
A fan attempt to play on an Earth interpretation of a bes'bev:
https://www.youtube.com/watch?v=yah1G6JkvjQ
Instructions for a different fan attempt at an Earth interpretation of a bes'bev (you'll need to join the Project Shereshoy server; see the home page for a link):
https://discord.com/channels/862865338084229180/865048761395052554/1002902222247575653
Picture (plastic pipe): https://discord.com/channels/862865338084229180/865048761395052554/1002899646923931718
Picture (metal pipe): https://discord.com/channels/862865338084229180/1158776447733862450/1159848393741439146
Playing the metal version: https://discord.com/channels/862865338084229180/886411192342573096/1025489616855367691
Quote from Republic Commando: 501st:
Only a Mando would create a musical instrument that doubled as a weapon.
Wad’e Tay’haai had shown up with his bes’bev, an ancient flute made out of beskar, playing tunes that Jusik didn’t recognize. He thought he didn’t, anyway. It was only when he tried to hum them to himself that he realized what they were. The marching song “Vode An”—learned by all clone troopers bred on Kamino, the only Mando’a language that most of them ever heard—sounded totally different played as a lament.
Tay’haai held out the flute to Jusik. It was painted a deep violet, like the man’s beskar’gam. “Want a go?”
“I’m not musical.” Jusik took it anyway, held it as Tay’haai demonstrated, and blew across the lip plate. The bes’bev remained stubbornly silent. When he balanced it in his hand, it had a pleasant heft to it. “So you can use this as a club. Which is probably the only use I’d get out of it.”
“It’s made for stabbing.” Tay’haai ran his fingertip along the end to indicate the diagonal cut, like a quill stylus. “Bleeds out someone very efficiently.”
“Why have a flute that’s a weapon?”
“Maybe we just don’t like music critics.”
Tay’haai began playing again, and Mird didn’t so much as howl along with the music as whine to it. Astonishingly, the strill managed to hit at least half the notes, sounding like a drunk who couldn’t remember the words but was doing his best to join in. A’den only made matters worse by howling along, too, which drove Mird into an operatic frenzy. It was the first time Jusik had ever seen Vau laugh uncontrollably.