Bright or brightly?

Question

A little known fact is that William Blake was a talented musician who would sing his poems. Unfortunately no sheet music of his poems exist, meaning the actual melodies he specifically used are unknown. But musicians have adapted Blake's poetry into song, and through that we can get glimpses of the music of Blake's poetry.

I'm interested in Sherri Poterfield's adaptation of William Blake's The Tiger. I found a really nice recording of a performance of Poterfield's piece on YouTube; listening to the video will give a better sense of the piece than reading the lyrics.

One of the things that interests me is that while the very first line of Blake's text is:

Tiger tiger burning bright

Poterfield made the decision to begin with:

Tiger tiger burning brightly

What is the reason for that change?

Answer 1

I have never met Sherri Poterfield so obviously I can only speculate on why she made this choice. But that I will do!

The Poterfield's melody begins with a musical structure that is called a "Satz" (or sentence). A Satz consists of two halves: the presentation and the continuation. The presentation has two halves: first comes an "idea", or a motif (musical rather than literary), then a (mostly varied) repetition, both parts are of equal length. The continuation is slightly hairier but in the textbook case the continuation is the same length as the presentation, yet doesn't break apart in two halves and, while based on it, does not literally repeat the full motif from the presentation.

A Satz is a very old, very reliable and very common thematic structure, especially for a beginning, and Poterfield decided to open the piece with one. This means, however, that she needs a melodic idea she can repeat. The idea of a Satz is generally very short, in this case 4 notes (which is not at all unusual, compare Beethoven's fifth symphony), since "tiger tiger" is 4 syllables. However, to repeat the idea she needs another four, while "burning bright" is only three. A (small scale) Satz is a very rhythmical structure, usually the variation of the repetition is a transposition or a melodic variation (and the Poterfield setting of The Tiger starts with an, apart from the text, unvaried repetition), not a rhythmical variation (especially not such a big one – omitting a quarter of the material). In addition, a common technique for the continuation is shortening the initial motif, so doing that in the presentation creates problems in this area too.

In conclusion, adding the extra syllable is very convenient (but by no means necessary) for the melody.

Answer 2

Poetically, metrically, the line as Blake wrote it is trochaic tetrameter with a catalexis (missing syllable). Brightly makes it trochaic tetrameter, but ruins the line.