BackgroundProlongation, as described by Music Theory, alludes to certainmusical events that remain active in the musical ‘flow’although they are not physically present. However, how isprolongation experienced and which its nature is, are unansweredquestions. Based on previous research it is possibleto assume that prolongation, as a phenomenon of musicstructure, is a factor that might organize the way in whichthe listener experiences tonal music. In a prior study, weused the click-detection paradigm and measured the SubjectReaction Time (SRT) in order to find evidence of prolongationas a constituent structural unit. If prolongationhave incidence in the way the listener represents music, aslong as the process of attending progresses, the study of theprocess of acquisition of this ability is a matter of relevance.2. AimExplore evidence about the acquisition of the experience ofprolongation as a constituent structural unit while attendingto music.3. MethodThirty children (6-14 years), sorted in three age-groups, hadto listen to 20 trials: 1) 10 trails: 5 melodies with a clicksuperimposed in two different positions: i) at the boundary- between the last note of the prolongational unit and thenext structural note in the musical sequence, ii) before theboundary (1 sec. before). 2) 10 trials: the same 5 melodiesin which the metrical position of the prolonged final tonewas modified, in order to monitor the influence of metricalfactors, with the clicks superimposed according to similarcriteria. We assumed that the more stable the event in whichthe clicks is located, the faster the SRT.4. ResultsResults show faster SRT for clicks at Boundary Positions, asit was hypothesised. Furthermore, younger children seemto have slower SRT than older children. As in the studywith adults, metrical position at the prolongation boundarywas a non-significant factor, although it could be observed atendency of the youngest children to be sensitive to metricalposition.5. ConclusionsResults bring evidence about the prolongation organizingthe listener’s experience while attending to tonal music sincechildhood. However, we have reasons to think that in youngerchildren responses could be influenced by metrical positions.