The unglossed headword, a present participle in the masculine nominative singular, is given as ludia/zwn here and in Photius lambda438 Theodoridis, but in Aristophanes -- see below -- and Hesychius lambda1352 it is ludi/zwn; cf. lambda 785.
[1] For Magnes see generally mu 20, where his play Lydians is mentioned. The present allusion to it derives from ancient comment on a passage partially quoted there, Aristophanes, Knights 522-523 (web address 1), which has a string of present participles (one referring to, and characterising, each of Magnes' plays) which includes ludi/zwn.
[2] The verb here -- plural because of the play's plural title -- is uncertain. Some Suda manuscripts (GVM) give it as dieskeda/sqhsan, "were dispersed/scattered/rejected", and that might be right as a reflection of what Aristophanes' chorus says about Magnes having been 'driven off the stage' when elderly. But more probably dieskeua/sqhsan, printed by Adler and also in Photius (above), is correct, since it seems to be clarified by Hesychius (above): there Aristophanes' reference to "Lydianizing" is explained as "dancing; on account of the Lydians [sc. of Magnes], which are preserved but have been revised"; sw|/zontai me/n, diaskeuasme/noi de/ ei)sin. For diaskeua/zw in this sense see LSJ s.v., IV.1.
[3] Greek Anthology 7.18.5-6 (Antipater of Thessalonica). For Alkman see alpha 1289.