Kaspa’s block reward decreases every month by the same proportion, so twelve monthly reductions halve the reward. This live issuance schedule is called the chromatic phase because each reduction matches the frequency ratio of one downward semitone in an equal-tempered musical scale. [1]
How the reward decreases
A block reward includes newly created KAS, called the subsidy, and transaction fees. The monthly schedule controls the subsidy, not the fees paid by people using the network. [2]
The chromatic phase began in May 2022, following the initial pre-deflationary phase. Its starting subsidy was 440 KAS per block, when Kaspa produced one block per second. Before that transition, the fixed subsidy had been 500 KAS per block. [1]
Each month, the subsidy is multiplied by 0.5^(1/12), approximately 0.943874. That means a reduction of about 5.61% each month, measured against the previous month’s reward. Twelve such steps multiply together to give 0.5, leaving half the starting reward. [1]
The schedule defines a year as 365.25 days and a month as exactly one-twelfth of that year. Its “months” therefore mean fixed schedule intervals, not calendar months of different lengths. [1]
Why a musical scale?
In equal temperament, an octave contains twelve equal semitone steps. Moving down one octave halves a note’s frequency. Kaspa uses the same relationship: twelve equal proportional reductions halve the mining subsidy. [1]
The starting number also reflects music: 440 is the frequency in hertz of the note A4, the familiar tuning reference. The tokenomics description calls each monthly interval a “semitone” and each schedule year an “octave.” [1]
The link to music is only mathematical: the subsidy follows a fixed, predetermined schedule, and music supplies the pattern and the names. [1][3]
Faster blocks do not mean faster issuance
The policy sets issuance over time, rather than keeping the same subsidy regardless of how many blocks are produced. When Crescendo increased the block rate to ten blocks per second, the subsidy per block was divided by ten. Ten times as many blocks therefore did not mean ten times as many new coins. [1][3]
For the detailed description of the monthly ratio, the musical terminology and the initial issuance phases, read the Kaspa wiki’s Tokenomics page. Its discussion of a future block-rate increase predates Crescendo; that adjustment has already happened, as described on the community-run kaspa.org site. [1][3]