Scottish trad is built around Highland pipes, fiddle, button accordion, clàrsach (the small Celtic harp), and unaccompanied voice. The instrumental core is three dance forms — the 4/4 reel, the 6/8 jig, and Scotland's distinctive strathspey (a moderate-tempo 4/4 built on the Scotch snap, a short-long rhythmic inversion) — strung together into 'sets' that a single track can sustain for several minutes. The vocal side splits into two Highland Gaelic strands: waulking song (Puirt à beul), the choral labour music sung by women beating tweed cloth into shrunken finish; and mouth music, in which singers vocalise Highland pipe and fiddle melodies through nonsense syllables — 'voice standing in for instrument.'

Scotland's musical tradition splits along the old cultural line between the Gaelic-speaking Highlands and Islands (Hebrides, Shetland, Orkney) and the Scots-speaking Lowlands. The Highlands preserve a two-tier structure: ceòl mòr ('big music,' the ceremonial pibroch played by clan pipers) and ceòl beag ('small music,' the dance repertoire). The Islands added the female-choir waulking song tradition. The Lowlands rested on the fiddle, whose standard repertoire was set by Niel Gow (1727–1807) and later James Scott Skinner (1843–1927). The Highland Clearances of the nineteenth century halved the tradition-bearer population, but Cecil Sharp, Alan Lomax, and others recorded the tradition systematically in the twentieth century, and the 1966 Traditional Music and Song Association (TMSA) became the national preservation apparatus.

First, get used to the Highland pipes' idiosyncratic tuning. The pipe scale doesn't sit inside Western equal temperament — the A tunes about 20 cents sharper than the modern concert-pitch A (440 Hz). That 'in tune yet slightly not' quality is where the instrument's characteristic ring comes from. Then listen for the Scotch snap in strathspeys: an eighth followed by a dotted sixteenth, embedded through the 4/4 in a way that sends every phrase-end jumping. The smaller pipes (Border, small pipes) are indoor instruments with a much quieter voice and belong to a separate tradition from the Highland pipes proper.

Start with Niel Gow's 'Niel Gow's Lament' (composed 1784 for his late wife) as recorded by a contemporary fiddler such as Alasdair Fraser. Then Silly Wizard's 'The Valley of Strathmore' (1981), which pairs a fast reel with a slow strathspey so you can feel the Scotch snap arrive. For unaccompanied Gaelic singing, Julie Fowlis's 2005 recordings capture waulking song in modern studio detail. Solo Highland pipes: Gordon Duncan. And for the current standard, the trio Lau — Kris Drever (voice), Aidan O'Rourke (fiddle), Martin Green (accordion) — has rewritten what modern Scottish trad sounds like.

'Hotaru no Hikari,' the graduation and shop-closing standard every Japanese person knows, is 'Auld Lang Syne' — Robert Burns's 1788 setting of an older Scots folk melody. Meiji-era Japan adopted it as a school song, and it has since become so integrated into Japanese daily life that most Japanese people do not consciously associate it with Scotland at all. Yet it is arguably the most widely sung Scottish traditional melody on the planet outside Scotland itself. The Highland pipes remain part of the British Army's regimental music, and Scottish regimental piper groups have appeared at Japan Ground Self-Defense Force Music Festivals (Nippon Budokan, most recently 2015).