When I first became aware that some chant daimoku as Namu Myoho Renge Kyo; I found it sort of emotionally upsetting. I thought Namu was only to be used for hiki or prolonged  daimoku.  To me, Nam Myoho Renge Kyo was the rhythm of the universe.  However, I could not help but notice that Nam is always written 南無 ~~ two characters. I was taught that meant  2 syllables and two beats, so it was confusing. Meanwhile, I got upset with Soka Gakkai and NST. I started chanting Namu Myoho Renge Kyo to be different from them.  At that point, I had not figured out the phonetic, rhythm, and tempo issues.

Actually, using Nam or Namu makes no real difference as to meaning. Buddhists who speak either Indic or East Asian related languages would likely feel comfortable changing from Na Ma / Na Mo / Na Mu  to Nama / Namo / Namu to Nam’. That is sort of like an English speaker changing from can not to cannot to can’t.  Or from would have to would’ve to wudda. For some reason, we overseas Soka Gakkai and Nichiren Shoshu Hokkeko got all hung up over what is actually a matter of beat, pace, and phonetics.

I suspect this was not due to our higher natures. People often think those from other places talk funny. Years ago, a friend of mine from Chicago made fun of the way I pronounced okra. To him, it sounded like okrey. Actually, I know people from very rural areas and far southern Illinois who do pronounce it okrey.  I do not. Meanwhile, I have noticed that when people from Chicago or Wisconsin say college, it sounds like cowllege, at least to me.

In Missouri, the name of that State is pronounced mizzourah. Older people from New York or New Jersey have this ‘r’ thing. They will pronounce er, or, aw, etcetera  as ‘oi’ if it’s in the middle of word, as in Joisey, goil (girl), or noive (nerve) .  At the end of a word, it becomes ah, as in  doctah (doctor).  Then a final a becomes er, as in dramer (drama), or sofer (sofa).  Meanwhile, toilet becomes terlet and saw becomes sawr. A lawyer is a loiyer; a New Yorker is a New Yoikah.

Anyway, methinks that our ‘baser’ or ‘lower’ self tends to be rather ethnocentric; which is probably extended ego-centrism.  For most of us, our initial gut response to the unfamiliar tends to be vague feelings of discomfort and/or anxiety.  Meanwhile, something can happen that causes us to rebel against the familiar, and we might find ourselves  attracted to the different or exotic.

Back on topic,  as i see it right now, Namu or Na Mu is a matter of rhythm, not pace or tempo.  Namu is one beat; Na Mu is two beats.  The 5 characters Myo Ho Ren Ge Kyo each have one beat, 5 beats total. For more meditative chanting, I generally use 7 beats — Na Mu Myo Ho Ren Ge Kyo. As long as I stick with 7 beats, this has no little or affect on pace.  I guess adding a Mu in there might use a nano second or so of time?

Now, for devotional or prayer chanting, I usually use 6 beats. So Namu gets one beat. There are places in the Sutra reading where 2 syllable words only get one beat.  One example is Hon Matsu Ku Kyo To 本末究竟等.  Matsu 本 is two syllable but one character, so it only gets one beat.

This does affect pace. When we recite the sutra at a fast pace, we elide matsu, so it comes out like Hon Mak_Ku Kyo To.  There are even places where two syllables get one beat. Those are transliterated or borrowed words, such as Shakyamuni 釈迦牟尼.  Shaka 釈迦 and muni 牟尼 each get two syllables but only one beat. So at a fast pace, it come out like shak’ mun’ (shock moon).  Also, Shaka 釈迦 is actually shak_ka;  an elision of shaku 釈 + ko 迦.

The same thing happens with Namu. When we chant slowly, it is easy to give Namu one beat without eliding. However, when we pick up the pace, it gets awkward. So we drop that final vowel, and it becomes Nam’. Dropping a final vowel sound is a common elision in not only spoken Japanese, but also in Indic languages. Namah (silent h), namas (phonetic change), namo, namu, and nam’ all mean the same thing.

From the Digital Dictionary of Buddhism 電子佛教辭典  link

南無 Basic Meaning: namah (Skt. namas; Pāli namo) To take refuge in; submit oneself to, from to bend, bow to, make obeisance, pay homage to; an expression of submission to command, complete commitment, reverence, devotion, trust for salvation, etc. It is used constantly in liturgy, incantations, etc. …

As for tempo, the speed with which I chant depends somewhat on my intention. I tend to do meditative chanting at a slower pace; devotional or prayer chanting at a faster pace.  That works best for me right now. Finally, eliding Namu to  Nam’,   when chanting the 6 beats at a slow pace,  really makes no phonetic or rhythmic sense, but it does not bother me. Much.