In Hüseyin Sadettin Arel’s (1880-1955) works such as ikileme, üçleme, and dörtleme composed for Turkish makam music (TMM) instruments, and ‘kemençe beşlemesi’ project, which he approached especially from organological perspective, can be considered as a kind of a statement that polyphonic makam music can be performed with TMM instruments. Arel presents a ‘pitch’ and ‘education’ system built on the pitch system of Western music in order to legitimize TMM. A similar inspiration can be seen in his polyphonic instrumental compositions. The studies on the kemençe beşlemesi until today have remained in historical and organological scopes, the work has not been performed until today, and no harmonic or makam analysis has been made. In this study and in our PhD thesis, the subject has been discussed for the first time in the direction of musical and harmonic analysis. In this study, which can be divided into two parts, a summary of the kemençe beşlemesi project is given in line with historical sources, and the effect of nationalization on the beşleme and the contribution of the modernization approach to the project are briefly mentioned. In the second part of the study, the instruments, musical terms, clefs, unusual key (makam) signature usage in TMM and the harmonic structure of the kemençe beşlemesi are analyzed. Arel added the nut to the kemençe, to equalize the length of the strings and named the kemençe he formed as the ‘soprano kemençe’. Like the register of the violin family in the West, he constructed the idea of ‘kemençe beşlemesi’, which he named as alto, tenor, bass, and double bass kemençe. While this design proved that the violin family of the West could be formed with an TMM instrument, Arel also aimed to establish a new type of traditional instrument ensemble. The book ‘Asri Kemence’, written by Zühdu Rıza Tinel in 1922, where he gives organological suggestions and advice on the kemençe, and mentions that the kemençe beşlemesi was formed as an example from the four-stringed kemençe and violin family, is one of the most important sources presenting the first ideas of the beşleme. This study examines several examples in the Beşleme no. 1, which is written for five different instruments, consists of 200 measures, and has many sections in it. In this context, the parts that we think will reveal Arel’s understanding of composition have been selected and exemplified from the work, which has been extensively explained and analyzed in our PhD thesis. In the Arel-Ezgi-Uzdilek (AEU) system there are 24 pitches in an octave and the intervals are not equal. For that reason, in the harmonic analysis of the work many types of chords were encountered, determined and listed with comma values of the building intervals. The harmonic analysis was made within the scope of tonal harmony terminology with additional chord types. In addition to chords like major, minor, augmented and diminished, we encounter a wide range of chord types in the piece. This is because in the TMM framework, the AEU system divides a major second into 9 commas (koma). In addition to the use of free counterpoint writing style in the beşleme in general, homophonic passages are also encountered from time to time. In the piece, G clef (treble clef) for the ney (reed flute), G clef for the soprano kemençe, tenor clef for the tenor kemençe, alto clef for the alto kemençe, and the F clef (bass clef) for the bass kemençe are used. There is a register that exceeds five octaves. Key (makam) signatures, separate instrument parts, pizz., rallent., octave sign, ritardando, slurs, etc., which are not very common in TMM notation system, and meticulously including technical terms such as tempo and dynamics are important in terms of their contributions to TMM instrumental music. The form of the beşleme can be considered through-composed in Western music: it is not associated with a certain theme, is free-flowing and possesses an uninterrupted structure. Considering the quartet and quintet instrument groups in Western music, Arel’s use of four types of kemençe and ney instrument in the kemençe beşlemesi can be associated with the presence of woodwind instruments as a supporting element in forms such as divertimento and serenade, especially in the Classical Period. The reasons such as the fact that the piece was not published, and that it contains difficult passages in terms of TMM instrument performance, have hindered the performance of the piece until today. Examination and analysis of all polyphonic works of Hüseyin Sadettin Arel, together with his work called Beşleme, will also shed light on his idea and movement of blending makam music with polyphony.