The headword, in the genitive plural (as direct object of a verb of hearing), is taken from Aristophanes, Acharnians 1042, and is the only use of this neuter noun known to us. The first part of the entry is taken from the scholia to the line. It is important as evidence for the sense of o)/rqios as 'sharply rising in a shrill tone' of tension and anger. The noun a)na/tasis (also used of the acute or rising accent) and the verb a)natei/nw from which it is derived denote the same tone of speaking that rises upwards in tension, either of threat or of boasting. See LSJ entries at web address 1, web address 2, and web address 3.
For the well-known o)/rqios no/mos, 'steep-rising style', see also omicron 575, omicron 574, alpha 1701, alpha 1122, chi 171, and cf. West 352-53 note 119. See also omicron 585, with a pun of Aristophanes on its similarity to o)/rqrios 'dawn' of a cock's cry.
West describes the nomos of Athena as 'probably a standard item in the Panathenaic musical contests' (West 216 and note 65). It was in the enharmonic genus and the Phrygian mode (ps.-Plut. De musica 1133ff., 1143B-C; Plato, Cratylus 417E). It was, however, according to West, probably in 'something like dactylo-epitrite', for it is identified in the scholia to Euripides, Orestes 1384, with the "chariot" nomos (a(rma/teios no/mos), a dactylic rhythm. There is here, then, an unexplained contradiction of the usual hypothesis of the rhythm on which the "steep-rising" nomos was based (see omicron 575).
The story of Timotheus the piper does not illustrate the "steep-rising" citharodic style, under discussion here. Rather, it is discussed as a piper style at chi 171. Timotheus' encounter with Alexander (sc. the Great) also appears at tau 620 and alpha 1122 (cf. Dio Chrysostom, Or. 1.6ff.; Anna Comnena, Alexias p.4.1; Eustathius, Commentary on the Iliad 11.11). If this is Timotheos of Miletus, tau 620, he was apparently a piper before he became a citharode (i.e. someone who sang his compositions in accompaniment to his playing of the cithara). For the Milesian's life and works, see OCD(4) 1484 'Timotheus(1)'; RE 6A (1937) 1331-37; T.H. Janssen Timotheus, Persae (1984); West 361ff.; Greek Lyric, ed. D.A. Campbell (Loeb edn., 1993), vol. 5. 70-121; J. Hordern, The Fragments of Timotheus of Miletus (2002). However, West p. 361 points out that the performing days of the Milesian, born c.450, can hardly have extended very far into the fourth century. Synchronicity with Alexander is impossible: T. of Miletus and T. the piper are homonyms from different eras.