Between thrash and the European melodic tradition there is a band of records that belong entirely to neither, made mostly between 1983 and 1987 by groups who were too fast for heavy metal and too melodic for what California was doing.
Speed thrash is not a real genre name and it is a useful description, and the bands in it are among the most consistently overlooked in this whole history.
Exciter

From Ottawa, and the founding case. Heavy Metal Maniac in 1983 is contemporaneous with the first Metallica album and owes it nothing, with a singing drummer, melodic riffs and thrash aggression in the same three minutes. Whether it is thrash or extremely fast heavy metal is a genuine argument rather than a settled one.
Agent Steel

Los Angeles, and the clearest example of the hybrid: thrash riffs and thrash tempos with John Cyriis singing in a high clean register over the top, and lyrics about extraterrestrial visitation. It should not work and it does.
Anvil
Toronto, and earlier than almost everybody. Metal on Metal in 1982 was faster and dirtier than anything a signed North American band had released, and both Lars Ulrich and Scott Ian have said in print that they took it apart. Anvil got nothing for it except forty years of citations.
Razor
Guelph, Ontario, prolific and relentless, and considerably closer to pure thrash than the others here. Evil Invaders in 1985 is as fast as anything from California that year.
Hirax and Whiplash
The American end: Hirax in southern California with a very high vocal over extremely fast material, and Whiplash in New Jersey playing faster than was reasonable. Both are frequently filed as thrash and both have one foot in the older tradition.
Helloween and the fork
The German case, and the reason the categories separated. Walls of Jericho in 1985 is fast, aggressive and melodic, and it is where the European tradition turned towards singing, virtuosity and eventually choirs. Within three years there were two audiences with almost no overlap.
| Album | Band | Year | Country | Which way it leans |
|---|---|---|---|---|
| Metal on Metal | Anvil | 1982 | Canada | Towards thrash, early |
| Heavy Metal Maniac | Exciter | 1983 | Canada | Genuinely both |
| Evil Invaders | Razor | 1985 | Canada | Thrash |
| Skeptic's Apocalypse | Agent Steel | 1985 | United States | Thrash with a singer |
| Walls of Jericho | Helloween | 1985 | Germany | Towards power metal |
| Power and Pain | Whiplash | 1985 | United States | Thrash |
| Raging Violence | Hirax | 1985 | United States | Both, loudly |
Why the category is useful
Because it explains a set of records that otherwise sit awkwardly in every account. A listener told that thrash means shouted vocals will bounce off Agent Steel; a listener told that speed metal means Helloween will not know what to do with Exciter.
Naming the overlap does two things. It rescues half a dozen very good albums from being filed as failures of categorisation, and it makes visible the moment in about 1986 when two traditions that had been the same thing stopped being it.
What happened to them
Badly, mostly, which is the recurring theme of this history. Exciter kept going in various forms and never got the credit. Agent Steel dissolved in 1988 amid line up chaos and reformed decades later. Anvil became famous in 2008 for a documentary about how unsuccessful they were, which is a genuinely strange way to finally get recognised.
Helloween, alone, prospered, because the melodic tradition turned out to have a much larger European audience than the aggressive one, and by 1988 they were selling out halls that no thrash band could fill in Germany.
Several of these bands also had the visual identity to go with the sound, which is its own subject: Thrash Metal Mascots. The full map is in the bands you need to know.
What the records actually sound like
Worth describing precisely, because the category is defined by a combination rather than by a single feature.
The rhythm guitar is thrash: palm muted, downpicked, at speed. The riffs are melodic rather than chromatic, built on shapes that resolve, and they frequently harmonise. The drumming sits between rock and hardcore, with a fast rock beat rather than a consistent offbeat snare. And the vocal is sung, often high, sometimes with a shriek at the top.
The combination produces something that is exciting rather than oppressive, which is the real distinction. A thrash record wants to be relentless. These records want to be thrilling, and that difference in intent is audible before any of the technical features register.
Where to hear the fork happening
A short exercise. Play "Fast as a Shark" from 1982, then "Heavy Metal Maniac" from 1983, then "Walls of Jericho" from 1985, then "Bonded by Blood" from the same year.
The first two are the shared ancestor. By 1985 the last two are audibly separate musics made from the same parts: one has a singer and resolving riffs and wants to lift you, the other has a shouter and chromatic riffs and wants to flatten you. Four songs, about fifteen minutes, and the entire history of the split.
The bands nobody can place at all
Beyond the hybrid there is a smaller set of records that defeat every category, and they are worth knowing about because they show where the map runs out.
Cirith Ungol were on the first Metal Massacre and sound like nothing else on it, or on anything since. Manilla Road from Wichita played fast, epic, badly recorded music for two decades with no scene to belong to. Blind Illusion made one album in 1988 that is thrash by tempo and something else entirely by harmony.
None of those bands were trying to be uncategorisable. They were working in isolation from anybody who might have told them what the rules were, which is the same condition that produced everything else in this article and simply taken further.
Why it matters which word you use
Practically rather than pedantically. A listener who is told that Agent Steel are thrash will put on Skeptic's Apocalypse expecting Slayer and get a high clean vocal and lyrics about extraterrestrials, and will conclude that they do not like thrash.
The same listener told that this is fast metal with a singer, sitting between two traditions, will hear the record for what it is. Genre labels are not about accuracy for its own sake; they are a promise about what the next forty minutes will contain, and a broken promise costs a band a listener.
Sources and notes
Years refer to original pressings. The category described here is a useful description rather than a term the bands used about themselves.