Polifonia is driven by 10 pilot studies that interact with and address the preservation, management, and study of musical heritage (MH). Focused on real-world music cases – such as Italian bell heritage, organs in the Netherlands, access to musical heritage for deaf people, and the identification of recurring melodic patterns – these pilots provide a means to validate Polifonia’s computational solutions; to strengthen the project’s outreach; and to integrate new scenarios, early-adopters and stakeholders. They are developed by interdisciplinary teams of researchers from the humanities and social sciences, and from computer science. This deliverable focuses on the mid-term validation of the four pilots that deal with the study of musical heritage: Tonalities, Tunes, MusicBo, and Child. It is a first step in the pilot validation process which will culminate in the D1.8 deliverable at the end of the project at M40. The main objectives at this stage are to a) present the individual pilot’s validation protocols; b) apply these protocols and present the results obtained so far; and, c) identify the lessons learned from the mid- term validation and address the avenues to be developed, strengthened, and reconsidered in view of the final validation. The validation protocols were designed on the basis of a shared validation framework developed in connection with WP5 and presented in detail in the second version of Polifonia’s socio-technical Roadmap at M18 (D1.2). This validation framework aims to ensure that: • O1: The pilot objectives reflect concrete needs expressed by the target communities and contribute to the state of the art; • O2: the methods and approaches are sound; • O3: the data on which the pilots are based are of sufficient quality to achieve the desired objectives; • O4: the objectives and results expressed are achieved; • O5: the resources, methods, and tools provided are made explicit and integrated into the Polifonia Ecosystem, interconnected through the PON and conveyed through the Web portal. The Validation framework is modular in nature. It includes core criteria with which all pilots must comply and specific validation methods for individual pilots or pilot groups. In table 1 the pilots considered in this deliverable (Tonalities, Tunes, MusicBo and Child) are identified in red. The compliance of the pilots to a set of common core tools, principles, and guidelines grants a methodological and conceptual coherence to the whole while leaving enough space for individual pilot-specific validation protocols: Applying a mix of XD and UX Design helps to unify the design process of the pilots, ensures that their objectives are in line with real needs, and enables to monitor the extent to which the requests and needs are actually implemented. The conformity of the pilots to the Ecosystem and its Rulebook ensures that all components are correctly referenced and documented. As a place for disseminating, enhancing and interconnecting the pilots, the Web portal helps to harmonize the way Polifonia’s resources can be presented, explored, and searched by both amateur and expert users. Finally, the Polifonia Survey provides meticulous documentation on the choices, orientations, resources, and objectives of each pilot and is the main source of information for the pilot’s individual validation strategies. The pilot specific methods cover the “input data” to assess the quality of the musical data (recordings, scores, historical texts, etc.) and to identify what changes have been made to the dataset to suit the pilot’s requirements. The validation of tools/means/software aims at verifying both the robustness and the ergonomics of the technical solutions implemented. Finally, the output/goal validation covers the validation of both the objectives and the results of the pilot. The following sections present the individual validation protocol for the four pilots, give a critical presentation of the results obtained, and draw lessons learned from these first validation attempts. The intermediate validation supposes that the pilots identify and describe all the elements and steps of their validation protocol. However, not all of these elements have yet to be fully defined and systematically put into practice at this stage. The second deliverable dedicated to the validation at the end of the project will have the threefold objective of a) updating the validation protocols; b) proposing their exhaustive application; and c) monitoring the resolution of problems, the optimization of performances, and the improvement of results since the present intermediate validation. A global overview of the methods, results, and lessons learned is proposed in the conclusion of the deliverable.