Writing a poem down originally had nothing to do with composing it and even less with 'writing a book'. In archaic Greece, writing served one main purpose: preserving for posterity. In other cultures, including the Mycenaean, administration was a major factor in the use and even invention of writing, in Greece there are no traces of that. The word sēma which Homer uses for written messages (Il 6.168) means "sign" with many applications but one of them is grave, tomb, grave-marker (Il 7.86-, 21.322, 23.255 and the "sēma" of a man long dead that serves as the turning point in the chariot race (Il 23.326-). The allusion is clear: the Iliad itself is a sēma, a grave marker for Patroclus, the best of the Achaeans (and of course for the poet himself). It must have been an exciting discovery for a poet: a way of preserving your work for posterity, where normally it would die with the singer. There may be apprentices, a younger generation, but they will sing their own songs, not yours. This brings us to a related function that a written text may have: it can be used for teaching.

There is some writing-related circumstantial evidence:

  1. Il 6.168 Bellerophon's σήματα λυγρὰ, pernicious signs
  2. Wade-Gery's theory that long η and ω were invented for metrical reasons i.e. actually created for the purpose of writing down the Homeric poems(1).
  3. Il 17.389-93 Stretching a cowhide for leather making
  4. pen? (Od 9.325-8) ref. also blindness
  5. ploughing - boustrophedon writing:

Admittedly this is meagre evidence, but it does make sense (see below) and it fits in with what we know about the Homerids and about the history of writing. It also offers an explanation for the remarkable degree of preservation of the text.

The Homerids

If you are a traditional professional singer you may have an apprentice who follows you around from performance to performance, carrying your lyre for you and trying to pick up the technique of epic singing by listening to many performances. This is not a very efficient method of learning and you probably cannot have more than one or two such apprentices in a lifetime. They will know the "formulas", the storylines and the technique of performing them before an audience but they will not know your composition by heart. The idea that a person could learn it by heart by just listening to performances seems rather farfetched to me. So, what to do if you are a not-so-traditional world-famous singer who composed a monumental work, setting afire the people's enthusiasm wherever you go, inspiring young men to come to seek you out because they want to learn this?
You start a school. You find a place out of the way of population centers but easily reachable and there you receive them and teach them your songs. For this you need a written copy. Without that even a voice of bronze will not be strong enough to keep singing the songs to them. So first you will have to teach them to read and write using your own poems. This works both ways, for your pupils can then help you with the major task of writing down the complete poems. Several problems have to be solved: what to write on (cow- and sheepskin? see Hdt. 5.58, possibly also Il 17.389-93), what to write with (a carefully shaped pen of olive wood, its point hardened in the fire? Od 9.319-) and what to use for ink.
All this may give you the reputation of being the world's first schoolmaster and, since they do not know your real name, the nickname "Phoenix" because of the Phoenician letters you are always occupied with.

view of Volissos harbour
Modern Volissos, a valley surrounded by high hills

Where would you live? You will want to be out of the way of powerful noblemen and cities who would use your fame for their own purposes. Therefore mainland Ionia and mainland Greece are not attractive, an island seems most suitable - somewhere in between those who live where the sun rises and those who live where it goes down. Since you are always anxious to hear news from your old hometown Smyrna, you will want to be near one of the main shipping routes.
Now there happens to be a fertile and wooded island stretched out before the Cyclops' harbour, not near nor very far...there are soft and well-watered meadows and a harbour where you can beach your vessel and stay until the wind becomes favourable...(Od 9.116-42). There is a place where those sailing the route north of Chios across the Aegean to Euboia (Od 3.170-) actually do that(1).

Having finished the writing down of your magnum opus, the Iliad, and being too old to go on extensive travels like you used to, you spend your time composing a second large poem, meant to be performed by your pupils. Since none of them is able to string your lyre, they learn to beat the rhythm with a wooden staff. So they go to the festivals like Delos and to funerals and win the tripods in the singing competitions.

Il 18.373(2) [...] τρίποδας γὰρ ἐείκοσι πάντας ἔτευχεν
ἑστάμεναι περὶ τοῖχον ἐϋσταθέος μεγάροιο,
χρύσεα δέ σφ' ὑπὸ κύκλα ἑκάστῳ πυθμένι θῆκεν,
ὄφρά οἱ αὐτόματοι θεῖον δυσαίατ' ἀγῶνα
ἠδ' αὖτις πρὸς δῶμα νεοίατο θαῦμα ἰδέσθαι.
οἳ δ' ἤτοι τόσσον μὲν ἔχον τέλος, οὔατα δ' οὔ πω
δαιδάλεα προσέκειτο: τά ῥ' ἤρτυε, κόπτε δὲ δεσμούς.

He (Hephaistos) was making twenty tripods which stood by the wall of his well-built house and he was setting golden wheels under them, so they might go by themselves to the holy gatherings (or the meetings of the gods) and come back home again - a marvel to see.
They were indeed finished, except the artful ears had not yet been added and he was hammering to fix them.

In this way you could live out your life. Your daughter Eidothea will take care of you while you receive visitors and cultivate your position as an immortal who knows the sea in all its depths and who can magically change into every phenomenon on earth or in heaven. You can even tell those visitors which of the gods it is that prevents them from reaching their home. And, of course, you will be able to solve every riddle that they put to you.

Hidden in the episode in Phaeacia (book 7-), there may be some advice to newbie rhapsodes:
  1. arrive on a ship (accompanied by a 'herald'?)
  2. remain unseen, don't talk to anyone, go straight to the 'big house' (7.27-)
  3. enter it bravely (7.50-)
  4. Appeal to the lady of the house, clasp her knees (7.142-)? I wonder...
  5. make 'going home' your first point of business (7.223-)
  6. introduce, answer questions (7.238-)
  7. appear at the public feast (8.1-)
  8. sing in public (8.62-)
  9. watch the sports (8.108-) but don't compete or quarrel with the local people
  10. compliment your host (8.382-)
  11. take textiles (and whatever else they want to give) as payment (8.392-)
  12. sing (9.1-) in private circle
  13. travel on as quickly as possible

  1. This may be unprovable but it makes very much sense. If you turn the text into Archaic Greek, written boustrophedon and without word boundaries (see menu) it can easily be grasped that if the eta and omega were replaced by epsilon and omicron, the text would become even more difficult to decipher rhythmically.
  2. Someday there will be a town called Volissos nearby where even in the far future people will still remember their old schoolmaster.
  3. Note that this little joke is in the Iliad, in the Shield of Achilles. This to me is a strong point in favour of the theory that Homer added pieces to the Iliad when he was writing it down.