Pcpaqu [ˈp͜ʼǀ.pʼ.ǃʷ] is a musical engelang that sounds like beatboxing, featuring clicks, ejectives and mora-timed rhythm, but it also creates unusual non-naturalistic features in its phonology (eg. consonant pairs, beat-based prosody) and its phonotactics (eg. pulse groups, consonant hierarchy).

Consonants

There are no vowels, only six consonants, and none of them are pulmonic: 3 clicks, 2 ejectives and 1 percussive. Two of these consonants aren't even phonemic in any natural language:

• The voiceless bilabial ejective trill [ʙ̥ʼ] is pronounced similarly to [pʼ], but having the lips vibrate while releasing air; it can also be seen as a tense version, notated as [p͈ʼ].
• The dental percussive has the tongue strike the back of the upper teeth, retrograde to the tongue's movement in a dental click. There is no extIPA symbol for this phoneme, so I notated it as [ɾ̪̥]; it can alternatively be pronounced as a bidental percussive [ʭ], with the bottom teeth striking the upper teeth.

consonants	labial	dental	lateral	alveolar
eject./percuss.	pʼ <pa>; ʙ̥ʼ <fa>	ɾ̪̥~ʭ <ta>
click		ǀ <c>	ǁ <k>	! <q>
pair		p͜ʼǀ <pc>; (ɾ̪̥͜ǀ)		p͜ʼǃ <pq>

There also exist consonant pairs: they are two consonants that are pronounced sequentially within one mora, each equally taking up one half of the mora. Two pairs are phonemic, [p͜ʼǀ] and [p͜ʼǃ] (pairs are notated with ties), whereas the pair [ɾ̪̥͜ǀ] is just an allophone of [ɾ̪̥] when before another [ɾ̪̥]. [pʼ] is also an allophone of [ʙ̥ʼ] when after another [ʙ̥ʼ].

Secondary articulation

Clicks can also be palatalized or labialized, being Pcpaqu's equivalents to vowels. This is represented in the orthography: palatalized clicks as <ci, ki, qi>, labialized clicks as <cu, ku, qu> and neutral clicks as <ca, ka, qa>. If the click is part of a consonant pair, then the articulation isn't written, not being phonemic.

This could also be reanalyzed as a three-tone distinction, as palatalizing or labializing a click changes its spectral frequency to produce a high or low tone respectively (its plain version produces a mid tone). It bears similarity to the playing technique of the talking drum, where Yoruba or Akan messages could be communicated purely with the (three) tones the drum could make.

Prosody

Pcpaqu relies on mora-timed isochrony; one mora could be occupied by a solo consonant, a consonant pair or a pause (pauses separate words). This can be seen in the orthography, as each digraph represents a mora (eg. pcpaqu [ˈp͜ʼǀ.pʼ.ǃʷ] occupies three, pc-pa-qu). Because the duration of each mora is equal, it has a regular tempo to form rhythms on. The speech tempo itself is usually andante, being 69~112 BPM.

In terms of music, one mora is equivalent to a 16th note: a solo consonant is one 16th note, and a consonant pair is two 32nd notes. These morae are analyzed in groups of four, ie. in quarter note beats. The amount of beats in a measure isn't constant and depends on the length of the word; it can be described as having additive meter.

The beat determines the placement of words and pauses: the first mora of a word that isn't a click is placed at the start of a beat, and is stressed (or musically, accented). Therefore, how many morae of pauses between each word can change from attaching prefixes and suffixes.

>The | represents the start of a beat, and each .. represents one mora of a pause. Capitalization indicates stress:
|Fafaqupa|pa......|Pacikipa|capa (no affixes: three-mora pause)
|Fafaqupa|pa..cuqu|Pacikipa|capa (cuqu- prefix: one-mora pause)
|Fafaqupa|pacikici|Pacikipa|capa (-cikici suffix: zero-mora pause)

Stress

Stress, or accent, is non-phonemic: within a word, it's placed on the first on-beat mora, as seen previously, but any other morae that aren't clicks also have secondary stress. It should also be noted that the former consonant of a consonant pair has more stress than the latter, ie. the click, because it is at the start of a mora.

Phonotactics

There is no limit to how much morae a word can occupy. This is because Pcpaqu alternates between ingressive and egressive sounds, so the airflow is continuously moving inward and outward, preventing the speaker from running out of breath. Therefore, the limit is in the amount of consecutive consonants that have the same direction of airflow:

• Ejectives and percussives ([pʼ], [ʙ̥ʼ] and [ɾ̪̥]) have a maximum of two consonants, being four possible combinations: [pʼ.pʼ], [ʙ̥ʼ.ʙ̥ʼ] ([ʙ̥ʼ.pʼ]), [pʼ.ʙ̥ʼ] and [ɾ̪̥.ɾ̪̥] ([ɾ̪̥͜ǀ.ɾ̪̥]). The percussive [ɾ̪̥] doesn't actually affect airflow but is just put in the same group as the egressives.
• Clicks ([ǀ], [ǁ] and [ǃ]) have a maximum of three consonants, with [ǁ] and [ǃ] clicks usually not next to each other, eg. [ǁ.ǁ], [ǃ.!] and [ǁ.!] are rare.
• Consonant pairs ([p͜ʼǀ] and [p͜ʼǃ]) have ingressive and egressive airflow, so there isn't actually a maximum, but it usually is two pairs.

Consonants alternating airflow form pulse groups, which are sequences of strong stressed/accented morae (as ejectives, percussives and consonant pairs) followed by weak unstressed/unaccented morae (as clicks), eg. in pcpaqu [ˈp͜ʼǀ.pʼ.ǃʷ], pcpa [p͜ʼǀ.pʼ] precedes qu [ǃʷ]. These pulse groups are concatenated to form words, having additive rhythm.

However, as seen in the prosody example, clicks can also occur word-initially without strong consonants preceding them (eg. cuqu-paciki-pacapa), and vice versa, strong consonants can occur word-finally without clicks after (eg. fafaqu-papa). Pulse groups can thus be notated as #W^(3)/P^(2)S^(2)W^(3)/P^(2)S^(2)#:

• Hashes and slashes signify instances occurring only word-initially or word-finally.
• W = weak consonants, ie. clicks
• P = consonant pairs
• S = strong consonants, ie. ejectives and percussives

Most roots are a sequence of pulse groups and their strong consonants, similar to Semitic radicals, with the rest of the morae filled with [ǀ]. These types of roots usually have four to seven consonants:

>The root tacaca-pacacaca-facaca-fafa [ˈɾ̪̥.ǀ.ǀˌpʼ.ǀ.ǀ.ǀˌʙ̥ʼ.ǀ.ǀˌʙ̥ʼ.ʙ̥ʼ], has a consonant sequence of t-p-f-ff [ˈɾ̪̥-pʼ-ʙ̥ʼ-ʙ̥ʼʙ̥ʼ] and a pulse group sequence of 3-4-3-2.

Roots can then be modified by replacing [ǀ] with clicks [ǁ] and [ǃ], attaching prefixes and suffixes, and/or palatalizing and labializing clicks:

>Root: tacaca-pacacaca-facaca-fafa [ˈɾ̪̥.ǀ.ǀˌpʼ.ǀ.ǀ.ǀˌʙ̥ʼ.ǀ.ǀˌʙ̥ʼ.ʙ̥ʼ]
With transfix: tacuqu-pacakaca-faciki-fafa [ˈɾ̪̥.ǀʷ.ǃʷˌpʼ.ǀ.ǁ.ǀˌʙ̥ʼ.ǀʲ.ǁʲˌʙ̥ʼ.ʙ̥ʼ]
With prefix: cuqu-tacuqu-pacakaca-faciki-fafa [ˌǀʷ.ǃʷˈɾ̪̥.ǀʷ.ǃʷˌpʼ.ǀ.ǁ.ǀˌʙ̥ʼ.ǀʲ.ǁʲˌʙ̥ʼ.ʙ̥ʼ]
With suffix: cuqu-tacuqu-pacakaca-faciki-fafacikici [ˌǀʷ.ǃʷˈɾ̪̥.ǀʷ.ǃʷˌpʼ.ǀ.ǁ.ǀˌʙ̥ʼ.ǀʲ.ǁʲˌʙ̥ʼ.ʙ̥ʼ.ǀʲ.ǁʲ.ǀʲ]

As a result, the consonants in a word follow the patterns of the percussion instruments they sound analogous to within a rhythm. This forms a consonant hierarchy, as each consonant has different emphasis: (from strongest to weakest)

• [pʼ], [ʙ̥ʼ] and [ɾ̪̥] as the kick drum, indicating the start of pulse groups, similar to on-beats, having the most emphasis.
• [p͜ʼǀ] and [p͜ʼǃ] as the roll of a tabla, being adjacent to kick drum consonants.
• [ǁ] and [ǃ] as the rim click of a snare drum and the claves respectively, being in the middle of pulse groups, similar to off-beats.
• [ǀ] as a closed hi-hat, filling the rest of the morae, having the least emphasis.

That's all for now. I thought of the original idea for it two years ago, but only started working on it this year. All the examples shown are just currently nonce words, because the phonology section required a lot more detail than my other conlang, so that's it.