The Earl of Kildare is an opera composed in three acts based on the 1534 rebellion against English rule in Ireland of Thomas FitzGerald, the 10th Earl of Kildare, also known as Tomás an Síoda, or Silken Thomas. It is scored for a sixteen-piece orchestra, and has a cast of ten singers. The libretto is by Celia de Fréine. The principal method behind the composition is the assignment of separate tempo layers and interval sets to the important characters resulting in the layering of tempi in scenes where such characters interact. Tempo ratios are used as a means of creating varying degrees of friction between character interactions, the simpler ratios signifying a less conflicting relationship than the more complex ratios which are used to signify a higher level of conflict. Thanks to The Living Opera Company, a workshop-production of the opera, performed with piano accompaniment only, was mounted, and a DVD made of the resulting performance. The performance showed some flaws in the architecture of the music, specifically in the last two acts, where more or longer interludes were required to cover scene changes. These have been addressed. Additionally, there were composed some spin-off arrangements for different ensembles of music from the opera. These are included in volume 2. The composition shows that the use of tempo layering, in addition to other techniques, as a means of dramatic characterisation is a viable methodology for the composition of music-drama.