by Harav Moshe Wolfson, shlita [Rav of Beis Medrash Emunas Yisroel and Mashgiach of Yeshivah Torah Vodaas]
[Adapted from a shiur that was delivered under the auspices of Irgun Shiurai Torah and prepared for publication by Rabbi Yochonon Donn]
There are two types of song: one has words (this category would include the art of poetry) in which words are joined together to create a rhythmic pattern and a sense of uniformity. In this type, the feeling of enjoyment and relaxation that comes from hearing music results from the whole song including the words.
In the second type of song, the reason for the enjoyment it gives us is more obscure: it comes when notes are put together to create a wordless song. It is not logical that notes thrown together should elicit a sense of enjoyment in people, that wordless tunes can be enjoyed is a gift from Hashem.
Sefer Pe'as Hashulchan by Harav Yisrael of Shklov zt'l, cites the Vilna Gaon in saying that most of the secrets of Torah are hidden in the art of music and that without understanding music it is impossible to comprehend the Torah. This knowledge of music was given over to Moshe Rabbeinu on Har Sinai along with the rest of the Torah.
The Zohar even says that there is a heichal - an entranceway - in Shamayim that can be opened only with neginah (song). The Zohar relates that Dovid HaMelech approached that entrance only with the neginah of his Sefer Tehillim.
Keys to the Heichal
The seven major musical notes are called keys. Each of the seven keys opens a different door in Shamayim, and it is only through music that these entryways can be opened. Musicologists do not know why the term "key" is used, but it is quite possible that it is a tradition handed down from Yuval, whom the Torah identifies as the father of music.
When the Baal Ha'Tanya came to Shklov, the residents bombarded him with questions. Chabad sources say that he responded with only a niggun, which answered all their questions. As the Vilna Gaon explained, music opens the doors of Torah in Shamayim.
A Gemara in Arachin says that the kinor (stringed instrument) in the Beis Hamikdash had seven strings, but in the times of Moshiach it will have eight strings. There are seven major notes on a musical scale, and the seventh note corresponds to Shabbos, for Shabbos completes the kinor, so that even today one can sing. The seven days of the week are actually the seven tunes of Creation. When Shabbos - the seventh tune - arrives, the harp is complete. This is the reason why we usher in the Shabbos with kapitel 29 of Tehillim, which describes the seven kolos - since then we can proceed with song.
This is the reason for the minhag among Klal Yisrael of singing zemiros on Shabbos. HaRav Mordechai of Lechovich zt"l reportedly said that he would be able to believe that all the seven seas had dried up, but not that a Jew does not sing zemiros on Shabbos.
The reason people so enjoy songs is that the tones that form them have been combined ever since the six days of Creation. Some songs, however, only confuse a person, such as some modern-day songs that are based on, for example, the pounding of a drum, or on words that have no correlation to each other, such as many non-Jewish songs. While they have a tune, it is different than the accepted process of music.
This latter type of song leads to immorality, just as the tones of these songs have no relation to each other but are merely thrown together, immorality involves the relations of two people who are not meant for each other. Neither these songs nor illicit unions were predestined from Creation.
Seven Keys of Chesed
There is a fundamental difference between the seven ushpizin (the holy guests on Succot) and the twelve shvatim - the 12 tribes of Israel. Every Jew has a direct connection with the Ushpizin, whereas each shevet is a separate and unique entity, the shvatim are thus a symbol of disunity.
For every seven white keys, representing the major notes on the piano, there are five black keys, representing the minor notes, each of which is a half-tone higher or lower than the white key next to it. The black keys complement and harmonize with the white keys.
In general, someone who would play using just the white keys on the piano would be able to play only a lively song, while playing just the black keys would result in a sorrowful song of sadness.
It is likely then that another tradition handed down from Yuval is for the keys that play major notes to be white, for happy songs, while the black keys, which play the minor notes, are black, for mournful music.
White is a source of chessed (kindness) for Klal Yisrael (this may be one reason doctors wear white), on the Yamim Nora'im we wear white kittels. Black, on the other hand, represents the trait of gevurah (severity) and is a source and an expression of melancholy.
A song that is played using a combination of black and white keys mixes chessed and gevurah. Together the seven white keys and five black keys of an octave equal twelve, the number of tribes of Israel, which as mentoned above, can symbolize disunity. Such a song is appropriate only for galus. When Moshiach arrives, however, everything will be white, for there will be no atzvus (sadness).
Chazal tell us that when Moshiach comes, an eighth key will be added to music; this key will be a 'roundup' of the previous seven (similar to the all-inclusive kollel used in gematriyos).
In Sefer Tehillim (68:7) when Dovid HaMelech relates the events of our redemption from Mitzrayim, he says motzi asirim bakosharos - "(Hashem) releases those who are bound in chains". The Gemara explains that the word "bakosharos" is a combination of bechi and shiros - simultaneous crying and laughter. This is a song played with both the white and black keys. When Moshiach comes, however, there will only be shirah - a joyous song played with the white keys.